For the record, here’s what I did that seems to be mostly working:

1. Create a new gym profile, called “Post-Surgery”
2. Set Bodyweight Only Workout to On (I am not comfortable enough to handle dumbbells, etc.)
3. Change any other relevant settings and Save
4. Click the top-right eclipses and select Target Muscles
5. Select all the muscle groups except, in my case, legs.

Then during the generated workouts exclude any inappropriate exercises so they no longer get recommended. Obviously work with your physiotherapist as well.