i think the basic difference between taz and cr is best illustrated by how they both handle zone of truth
in cr you have to tell the truth, but you can choose to not answer
in taz you are compelled to tell as many truths as you can get out, question-relevant or not
question: did you murder that stranger
critical role: i don’t know who that guy is (technically not a lie, since he’s a stranger)
the adventure zone: NOT ONLY DID I MURDER THAT MAN, I WENT INTO HIS CLOSET AND LICKED ALL HIS VESTS BECAUSE THEY WERE VERY STYLISH AND I NEEDED TO MAKE SURE NOBODY ELSE WOULD WANT THEM
there’s something very special about Merle’s brand of Zone of Truth (and I guess Ango’s for that matter)
option 1: taz faerun just has weird zone of truth dynamics and is generally just a little too meta for its own good
option 2: the original two-sun planet employed magic with identical effects but slightly altered results than the magic in use in the rest of d&d canon – which means merle was the one who taught angus zone of truth