PLA is brittle, so can crack if overstressed. I’ve pretty much settled into a routine where I use clamps and blue painter’s tape and CA glue, so don’t feel the need to tighten too much, c.f.,
The injection molded clamps are glass-filled nylon.
ABS or Nylon should work well, but both are tricky to print and the former needs to be vented.
I’ve been using PETG as my all-around engineering filament and it has worked quite well, and prints easily and is supposed to be almost as safe as PLA — have you considered that? It’s a bit slippery, so maybe put some double-sided tape on the jaws, or if you have a dual-head printer use TPU for the clamping end?