Iaijutsu being casted is perfectly fine and has always been fine. What feels bad right now is the two back-to-back casts of midare setsugekka+tsubame gaeshi. not only does that mess with samurai's mobility, you're not allowed to use any gcd's between midare and tsubame without losing the latter. it also looks weird, like its obvious midare setsugekka's full animation wasn't designed around being spammed.