I think the biggest issue with these sorts of things is all the different platforms that need to be support.
Do you have any ideas on how you could automatically test how well different features render in different terminals and on different OSs?
You're right, and it's the main gap right now. We test against xterm-headless with thousands of property-based test iterations, but that's one terminal. I've been developing against a handful of others (Windows Terminal, Mac's Terminal, Ghostty) and real terminals disagree on more than you'd expect. Cross-terminal conformance testing is what I'm focused on next.