I don't think fast gpu rendering terminals should be mandatory for this kind of thing, and if you should have an option that facilitates the need for one then might I suggest falling back to something sensible rather than stalling out for forever when the user doesn't render glyphs as fast as you want them to?

either that or fail outright; dont waste my time.

My terminal has gpu acceleration disabled due to being wasteful with vram and while I don't use opencode I've ran the script and it was completely fine using minimal cpu.