I was going to reply with my answer but I tested it again and realised that actually in some cases the custom prompt is somehow being ignored, so I don’t truly know how good it actually is in opencode.
Poking around in the convoluted opencode source or the overstuffed github issues to try to make sense of exactly what is happening has convinced me to switch to pi as well, simply to have a thing I can more fully understand. I am using paseo anyway for the GUI on the Mac, so switching agents is easy enough and pi has always seemed like it might be the right choice in principle. Initially I just picked opencode as the easiest path but now it feels like the time.
That was basically the conclusion I came to after I spent a couple hours trying to puzzle my way through opencode's settings - extremely opaque and hard to tell what's happening. Pi is simpler, and i figure if I really need a better system prompt, that's literally what AGENTS.md is for, right?