On the most current version (v2.1.110) of claude:
> /model claude-opus-4.7
⎿ Model 'claude-opus-4.7' not found> /model claude-opus-4.7
⎿ Model 'claude-opus-4.7' not foundnot
claude-opus-4.7
Heck, mine just automatically set it to 4.7 and xhigh effort (also a new feature?)
xhigh was mentioned in the release post, it's the new default and between high and max.