Since players can enable the ‘retain consciousness during transfur’ rule so that they can retain consciousness during transfur and gain the traits of the variant instead of dying, can a similar mechanic be added for the original mc human npc's (e.g. the original villagers, wandering merchants, marauders, etc.)? ? (e.g. original villagers have a probability of retaining consciousness after being transfur, when only their model is changed without affecting their AI (e.g. trading, career system, etc.))

that'd be interesting but probably hard to implement, also you mean "keep consciouness"

so maybe it'd be cool if there were already transfurred (and ofc conscious) villagers, it would make sense if they were tf'd into "organic"/non-latex forms (or maybe those tf'd into latex forms can be very rare)

What he means is to add rules to human NPCs like villagers that are similar to the player's "gamerule keepConscious" game rules, such as "gamerule keephumannpccomscious < number>(%)"

It means that every time they get transfurred there is {number}% will they lose consciousness.

i think you meant "they"