That was not my experience. When I tried to use Opus for longer tasks with Copilot, it would fill up the context completely and then crash without any output, while still consuming premium requests. (At least from September 2025 to January this year. Haven't tried after that.)
On pi coding agent, it worked very well for me over the past few months, but started glitching more recently, just prior to this announcement.
Copilot has improved immensely in 2026. I'd say to give it a try again if you're up for it. It works about as well as Claude Code these days in my experience.