A couple of these exist in guitar pedal form for lv2 (which is a dead format): Mod Audio Dwarf, and pistomp.
Nothing for VST3 that I'm aware of. Maybe the new Akai stuff?
https://www.soundonsound.com/reviews/muse-research-receptor
https://www.soundonsound.com/reviews/muse-research-receptor-...
You can pick them up, often fully loaded with plugins, for a few hundred dollars. I wrote parts of the system. They were running Linux and fun to hack on.
I currently work in the professional audio industry and know of a few modern efforts underway to produce modern version of this, but I am not convinced there is market for such a device anymore.
I'm sure a lot of professional musicians would probably prefer to use something less fragile than a laptop, something you can rack up, with no pesky desktop OS niggles to worry about during a show. As you know many instruments today are simply dedicated VST runners with a handy physical interface, see Roland's Boutique and Aira synths. I have an MPC One which I love, it can run proprietary VSTs. Maybe such convergences have killed the need for a dedicated box.
I know for a fact new devices like this are on the horizon, but it just might not be the form factor that you are looking for.
It's actually a golden age for the MIDI fan but there's a lot of complaining to be done too about aspects of it. Cheapness and hooking you to a store being two big ones.