Bit on an update on Zen, it looks like Anthropic have blocked Claude usage outside of Claude Code, so if I did want to use Opus, it'd have to be through that. They might reverse it or OpenCode might find a way round it, but overall I'd say at this point its safest to assume, if you're starting fresh with this, you go with one or the other.

Still not sure which one I'll go with, though I can't say I feel too keen to get into Claude after that