Here’s the deal probably with weird shapes you’ll need more raycasts, raycats are continous collisions which are usually more expensive then discrere collisions. Discrete collisions is what the roblox physcis engine does.
However .Touched isn’t good for fast moving objects since it introduces the problem of tunneling.While continous collision implementations like raycasting solve this. But the tradeoff is performance.
Underneath the hood the physcis engine is constantly checking for collisions and when a collision is found it fires .Touched event. Even if you connect to it or not those parts are being checked for collisions, so .Touched isn’t less performant because if it was we would be seeing that lag in a game with lots of parts. Collision checks are already running in the backround what is expensive is what you connect when .Touched Happens.