Opus 5.5 medium is a real sweet spot for many many things. But. I got an unexpected refusal (for help creating a browser console script to convert a web-based streaming video to an offline-ready .mp4), which Opus 5.5 low happily provided.
Anecdotally, I have had Opus 5.5 decline a reverse engineering effort into a Zigbee gateway that I own.
DeepSeek did not have any issues with this using Claude Code as harness.