Cool stuff! I did some experiments with pre-rendering Milkdrop visuals for high-res uploading to YouTube which might be of interest to you. Not practical for realtime (I guess this is where OBS comes in), but pre-rendering is great for quality. Example video: https://www.youtube.com/watch?v=TyhisYKU2Dg
Some notes on the process: https://www.markneuburger.com/prerendering-music-visualizati...
Led to a side project called pasteur, a tool for baking visualizations into MP4 videos for sharing: https://www.pasteur.cc/