For what it's worth, I've been pretty happy with Hono + OpenAPI + Zod, which has worked very well for me in recent projects. From there, you can do client generation with a number of tools from OpenAPI, while Zod will do runtime validation against your Hono API implementation.
Definitely a cool idea... My only thought/suggestion, are you doing rendering even if the canvas is outside the current scroll region? I don't know if ThrreJS or your code already account for this scenario and simple leaves it alone.
Aside: Really would be cool to see a Donkey Kong Country style game as a browser-native 3d, not like the pre-rendered 3d on a 2d surface of the original game. Or, for a more 3D effect, similar to Crash Bandicoot games.
Congrats on the release... I'd probably post it to Hacker News as it's really OT here, I know you mention RIOT.js, but the project really isn't JS centric.
Interesting, though definitely a large composite component. Nice to see the MIT license, I seem to recall some SVAR bits being some GPL variant, but my quick look at the github repos seem to be MIT now across the board.