I found the Latin finally:
... Baptismi suscipiendi propositum, atque consilium, et male actae vitae poenitentia satis futura sit ad gratiam, et iustitiam, si repentinus aliquis casus impediat, quo minus salutari aqua ablui possint.
... with the key passage being "si repentinus aliquis casus impediat, quo minus salutari aqua ablui possint".
si = if
repentinus = unexpected / sudden
aliquis = some
casus = incident, occurence, event, generally with a negative connotation of being a bad event or a mishap
So to translate "casus" as "accident" is completely wrong. In English this implies some near-fatal or potential fatal incident, where there's nothing of the sort necessarily there in the Latin.
impediat = impede, get in the way of, become a hindrance to ... subjunctive mode, indicating a hypothetial possibility
https://classics.osu.edu/Undergraduate-Studies/Latin-Program/Grammar/mood/Conditions/conditions-latinThe Subjunctive Mood used in conditions is a special usage of the potential subjunctive. The potential subjunctive presents a state or an act, not as fact, but as existing in the realm of possibility.
"quo minus" = from / lest (often following forms of impedio)
salutari = saving
aqua = water
ablui = to be washed off or cleansed
si (if) followed by a negative construct such as "quo minus" has a similar sense as the Latin "ne", meaning lest.
si + subjunctive + quo minus together could easily have the sense of "lest something prevent them from being able to be washed by the saving water".
All this passage is saying is that the proper dispositions of an adult would suffice (with God) to overcome any obstacle that might get in the way of their being washed by the saving water.
It's silent about HOW, whether this means keeping them alive until their Baptism (as St. Fulgentius held) or by a Baptism of desire. It could be either one, but Trent doesn't go into it, as the point is merely that it's OK to defer Baptism for adults because if they have the proper dispositions, they will not die and go to Hell ... whether this means that the not die (non-BoD reading), or whether it means that if they die they won't go to Hell (BoD reading).
This text is inconclusive at best.