Ok. Again - I mentioned this earlier regarding "superfluous" - let's look at the actual language of Trent.
Canon 5 from Session VII on the sacraments says:
The translation of Denzinger that I am now looking at (edition 43 edited by Peter Hunermann), translates this as:
The key word here is "liberum," translated as "optional." As Trent says, this word liberum/optional is itself glossed, "hoc est non necessarium," or "that is, not necessary."
"Liberum" comes from "liber," and I believe is being used in the sense of "free or exempt from," - Charlton T. Lewis, Charles Short, A Latin Dictionary, līber (tufts.edu)
As you can see from reading the passage "as written," "not necessary" is being equated with optional or free or voluntary, as if the sacrament of baptism can be dispensed with because of, e.g, the truth that justification can come from a "desire for the sacrament."
That is what is condemned by Trent "as written;" that is the type of "necessity" Trent speaks of baptism as having: it is not optional, or something one can forego as not necessary.
This is a discussion in search of truth, and I'm no Latinist, so I welcome correction or another view.
I'd like to respond, but I'm not sure what you're saying. I believe that ANY type of necessity would be contrasted with "optional".
While Trent doesn't explicitly explain the type of necessity (absolute vs. relative, of means vs. of precept), I believe the unanimity of theologians hold that it's "absolutely necessary by necessity of means". I believe that one of the Catechisms often cited in favor of BoD asserted that it was "absolutely" necessary.
Even if it's absolutely necessary by necessity of means, there's still the question of whether that necessity is maintained by the theory that one can receive Baptism
in voto. After all, ...
the Sacrament is necessary to be able to have the
votum to receive it and
the
votum is necessary for justification
So by kindof like a "transitive" logical property, it would still be necessary even in a BoD scenario.