You are assuming the Catechism teaches BoD, it doesn't. It's typical for people who believe BoD to read into it. God will bring a person baptism, that is what it means by "avail". Also the Catechism is not infallible and your second statement doesn't mean what you are implying because the Catechism teaches that souls are created some time after conception and not immediadtely which is an error.

Yes this^

The catechism first off states that there is no danger of death involved, if there were, then the adult must be be baptized asap like infants who are more prone shall we say, to die at any time. However, when there actually *is* the danger of death, the very next chapter teaches that "In Case Of Necessity Adults May Be Baptized At Once."

To continue with  the first part where it says: "should any unforeseen accident make it impossible for adults to be washed in the salutary waters, their intention and determination to receive Baptism and their repentance for past sins, will avail them to grace and righteousness."

Note that "grace and righteousness" are attributes of the living, not the dead. Neither Trent nor it's catechism are talking about the attainment of salvation here, which is an attribute of the dead, not the living, which means quoting this part of the catechism to show it's contrariness to John 3:5 and Trent's application of it, is a non sequitur.

Also note that there is no mention of accidental death, only an "unforeseen accident," which could mean literally any unforeseen event *except death* that impedes the catechumen from receiving the sacrament as planned, anything from the priest having to reschedule due to an emergency, to the catechumen's car not starting, to whatever other "unforeseen accident" you can think of, except unforeseen accidental death.

How do BODers understand this teaching of Trent?

We don't INTERPRET it. The beauty of it is that we allow the (Church) Fathers, catechisms, canon law etc to interpret it...

 St. Alphonsus Liguori  "Moral Theology - (Bk. 6):

   "But baptism of desire is perfect conversion to God by contrition or love of God above all things accompanied by an explicit or implicit desire for true Baptism of water, the place of which it takes as to the remission of guilt, but not as to the impression of the [baptismal] character or as to the removal of all debt of punishment. It is called 'of wind' ['flaminis'] because it takes place by the impulse of the Holy Ghost Who is called a wind ['flamen']. Now it is de fide that men are also saved by Baptism of desire, by virtue of the Canon 'Apostolicam De Presbytero Non Baptizato' and the Council of Trent, Session 6, Chapter 4, where it is said that no one can be saved 'without the laver of regeneration or the desire for it.'"

1917 Code of Canon Law

On Ecclesiastical Burial - (Canon 1239. 2)
   "Catechumens who, through no fault of their own, die without Baptism, are to be treated as baptized."

We don't INTERPRET it. The beauty of it is that we allow the (Church) Fathers, catechisms, canon law etc to interpret it...

St. Alphonsus Liguori  "Moral Theology - (Bk. 6):

  "But baptism of desire is perfect conversion to God by contrition or love of God above all things accompanied by an explicit or implicit desire for true Baptism of water, the place of which it takes as to the remission of guilt, but not as to the impression of the [baptismal] character or as to the removal of all debt of punishment. It is called 'of wind' ['flaminis'] because it takes place by the impulse of the Holy Ghost Who is called a wind ['flamen']. Now it is de fide that men are also saved by Baptism of desire, by virtue of the Canon 'Apostolicam De Presbytero Non Baptizato' and the Council of Trent, Session 6, Chapter 4, where it is said that no one can be saved 'without the laver of regeneration or the desire for it.'"

1917 Code of Canon Law

On Ecclesiastical Burial - (Canon 1239. 2)
  "Catechumens who, through no fault of their own, die without Baptism, are to be treated as baptized."

But you must interpret it as it says quite clearly that "unless they are regenerated to God through the grace of Baptism,... they are born to eternal misery and destruction."

We already refuted the OP's misinterpretation, but as for the great Moral (not dogmatic) theologian St. Alphonsus, in his commentary on Trent's necessity of the Sacraments, as regards the sacraments he states:

"The heretics say that no sacrament is necessary, inasmuch as they hold that man is justified by faith alone, and that the sacraments only serve to excite and nourish this faith, which (as they say) can be equally excited and nourished by preaching.  But this is certainly false, and is condemned in the fifth, sixth, seventh, and eighth canons:  for as we know from the Scriptures, some of the sacraments are necessary (necessitate Medii) as a means without which salvation is impossible. Thus Baptism is necessary for all, Penance for them who have fallen into sin after Baptism, and the Eucharist is necessary for all at least in desire ( in voto)."

As for Canon Law, post the whole thing....

§ 1. Those who die without baptism are not to be accorded ecclesiastical burial.
§ 2. Catechumens who through no fault of their own die without baptism are to be reckoned as baptized.
§ 3. All baptized are to be given ecclesiastical burial unless they are expressly deprived of same by law.

I will admit that CL 1239.2 confuses me somewhat, personally I think it's error, but whatever it is, it's not teaching a BOD, and in light of 1239.1 it's a far cry from teaching a BOD.

The only way a BOD is salvific, is if you altogether remove the Divine Providence from it.... "There is no one about to die in the state of justification whom God cannot secure Baptism for, and indeed, Baptism of Water. The schemes concerning salvation, I leave to the skeptics. The clear truths of salvation, I am preaching to you. - Bread of Life by Fr. Feeney

I used to be real passionate about this subject, but because *only* those Catholic who are already sacramentally baptized argue for it, these days it's more of a leisurely way to pass time for me.

I guess I just find it strange that this topic can push so many emotional buttons.

Sorry did not meant to put all that in quotes, still learning how to use the forum.

Catechism of the Council of Trent (or Roman Catechism)
"On this class of persons, however, the Church was not accustomed to confer this sacrament immediately, but ordained that it should be deferred to a certain time, nor is the delay attended with the danger already noticed in the case of infants, for, should any unforeseen accident render it impossible for adults to be baptised, their intention of receiving it, and their repentance for past sins, will avail them to grace and righteousness"

"In Dominico Argo" encyclical by Pope Clement XIII
"As our predecessors understood that that holy meeting of the universal Church was so prudent in judgment and so moderate that it abstained from condemning ideas which authorities among Church scholars supported, they wanted another work prepared with the agreement of that holy council which would cover the entire teaching which the faithful should know and which would be far removed from any error. They printed and distributed this book under the title of The Roman Catechism. There are aspects of their action worthy of special praise. In it they compiled the teaching which is common to the whole Church and which is far removed from every danger of error, and they proposed to transmit it openly to the faithful in very eloquent words according to the precept of Christ the Lord who told the apostles to proclaim in the light what He had said in the dark and to proclaim from the rooftops what they heard in secret."

Since the encyclical of Pope Clement XIII declared that there are no errors contained within the Roman Catechism, and since the Catechism teaches that which would typically be referred to as "baptism of desire", "baptism of desire" is not erroneous, but the teaching of the Church.

May all come to the truth of Catholicism and the Pope (see "Catholic Truth" on YouTube for more information).

No, it doesn't. I've posted @1friarminor twitter post on here. fillmore boys are wrong. Friarminor was exposing this before fillmore boys came along. For me, they ruin this important subject added with some of their goofy videos they make too. Caritas has an interesting account  https://x.com/Caritas701/status/1404570564182765571

But hang on a minute. I must interpret it? I fear for my salvation too much to be interpreting something of such importance on MY own accord. I will always consult what the Church taught about it. If st Alphonsus is wrong, then please quote contemporary post-Trident APPROVED theologians who disagree with him. You downplay him as a fallible person (sure, he was no pope) but then you give me even more fallible priest of 20th century against him. Fr Feeney was no theologian, I must remind you.

Yes, you misinterpret Trent's catechism, there is simply no other way to come up with a BOD from the catechism. Did you read the snip I posted from that catechism? If not, please read it, then use that teaching to support a BOD.
And please do the same with what I posted from St. Alphonsus.
And Fr. Feeney was indeed a theologian, well respected and was a well known priest and theologian.

Error? So canon law of Church is in error? It is not a mere error than my friend. It is a hellish heresy which caused poisonous "error" that crept in the 1917 canon law promulgated by a valid pope? Excuse me?

That's my opinion and nothing more. First it says those who die unbaptized cannot receive ecclesiastical burial, then it makes an exception for unbaptized catechumens. Something seems to me to be amiss there. Whether I am wrong or not means nothing, because either way it's not teaching a BOD.