I guess you’re probably looking for someone who uses cursor etc to answer but here’s a data point from someone a bit off the beaten path.
My editor supports both modes (emacs). I have the editor integration features (diff support etc) turned off and just use emacs to manage 5+ shells that each have a CLI agent (one of Claude, opencode, amp free) running in them.
If I want to go deep into a prompt then I’ll write a markdown file and iterate on it with a CLI.
I noticed that OpenCode requires per their own website "a modern terminal emulator" - so, no problem in Emacs? Are you running M-x term?