I’m actually working on a really similar project. I’ve just started on it but if you have really strict quality requirements you might have to find workarounds to increase the visual quality of your cubemaps. If you’re alright with a little bit of blur I’d recommend doing what this guy did with a hollow cube. Let me know if you end up finding any cool tricks to increase your visual fidelity, the only one that I’ve found so far is disabling mipmapping on the cube mapped texture.