Tie-rod roll or heim flop creates that dead spot that makes steering systems like that poor for our knuckles. Jk and JL run different knuckles.
Yep, you could make the crossover setup work on a TJ I'm sure, but the amount of cost, time, and effort you'd put into doing it right would far outweigh any gains. This is what I've gathered from the research I've done at least.
I think this is why most people don't bother with this sort of stuff unless they're running aftermarket axles (i.e. RockJocks).