Another one is ps2x2pico. I've been using it in my retro machines and it works great. For my Logitech G305 mouse (1000hz), I have ps2x2pico configured to force a 100hz mouse polling rate so the cursor is super smooth in Windows 98 without needing to use a program like PS2Rate. For my Keychron S1 keyboard, N-key rollover works flawlessly.
https://github.com/dekuNukem/USB4VC
There's also a more recent project called HIDman, but only for PCs.
https://github.com/rasteri/HIDman