I would not think having the doctor basically “prescribe” activity would mean anything as far as volunteering for a job goes. Since this will not be reported to SS anyway, it becomes mute. Technically speaking, if you can volunteer for weekly work, then IMO they can see you being able to do this for money. I think the problem would be if you were volunteering your time beyond what SS would permit if it was an actual job. However, this does not mean SS would actually think this way. This is just one way to look at this situation.

I have never been investigated. My case has never been reviewed by SS. I have been on disability for over 15 years. So maybe my perspective on this is different for these reasons. So the usual disclaimer applies, IMHO and FWIW.