The WX5 especially with the VL70m synth feels like I’m playing a real instrument. I still bring the tenor sax to the gig but I leave the alto home, and sold the soprano. It does decent emulations of trumpet, trombone, clarinet, guitars, harmonica, and a few other instruments. Violin and flute not so good, unless I haven’t learned how to do it.
If you are interested, I know a guy who runs a commercial site dedicated to wind synthesis, and he usually has refurbished ones for sale, plus the two models by Akai and Roland still in production (I like the WX5/VL70m better than the Akai and Roland synths).
I gigged with musicians ear plugs for a long time and after a while you get used to them. It takes an adjustment. I suspect with violin as it is with sax, your hearing through the filters has to compete with bone conduction.
After you get used to the plugs, it starts to sound normal. I believe either Westone or Etymotic offers a 9db filter that might be right for Violin. I don’t know how loud a single fiddle plays, but an inexpensive sound meter might be able to solve that.
The rule of thumb for me is to not let anything over 85db (A weighted, slow response) reach my eardrum.