Ptosis overcorrected 21 days ago. Should I consider a revision now or 6 months later? (Photos)

Since you had one attempt at revision on the left eye and the problem persists, it may be better to wait for the full 6months. Either the surgeon under-corrected the left eye both times, or the left muscle is just very weak, in which case you may have to consider dropping the right eye a bit lower so that you will at least have more symmetry. With very weak eyelid muscles, you really have to wait many months to see it back to functioning normally.

If over correction is very obvious within the first week, I would consider early intervention, however at 21 days, it is probably better to wait the full 6 months to allow the swelling to resolve, and the scarring to soften substantially. As you lift the more droopy eyelid, the overcorrected eyelid may settle down even further (Hering's law).There are quite a few excellent Oculoplastic surgeons in the San Francisco area, as well as up and down the coast, if you would like second opinions. 

I will intervene early to lower an eyelid that appears too high right after ptosis surgery. When an eyelid is heavy, it is important to be very patient. Heavy eyelids often do open up over time. An important question is which side do you like more, the right side or the left side. If you are happy with the openness of the right side, I would recommend letting the eyelid heal and revising it in 6 months. What type of surgery was used for the ptosis repair: anterior elevator resection ptosis repair or posterior mueller's muscle conjunctival resection. Eyelid massage can happen but this should be medical supervised. You live in the Bay Area so it is likely you would need to travel to Los Angeles to get meaningful second opinions. 

In my experience, I would recommend waiting and allow full healing to occur. This will definitely evolve over the next 6 months and the chance of getting it as perfect as possible will increase if you allow for completion of the healing.  It takes a lot of patience! It may also be helpful to consult other surgeons to gather opinions as to the best approach for your particular situation. I wish you the best of luck!