Downcut endmills don’t work well in plastics — unless chip extraction is about perfect you risk recutting chips, heat building up, and melting.
The MC Etcher works great in harder materials — I’ve etched acrylic with it with great results:
We don’t have plastic feeds and speeds for V tooling in Carbide Create — I recall using a V endmill to V engrave some acrylic keychains, but that was on my Nomad, so was probably a 1/8" tool.