I think the dimpling is possibly caused by your mentalis muscle being strained. Did anyone you saw mention this? Maybe reversing the SG and reducing the vertical length would take the strain off and therefore resolve the dimpling, which happens when the chin muscle is hyperactive. Shortening the length of your chin would have a beneficial effect aesthetically, but not resolving the other issues you mentioned (philtrum length etc) would possibly mean you wouldn't be happy after having it done?
I think a full jaw revision would give you the best overall aesthetic outcome, but obviously it is not only expensive but a lot to go through again, so nothing anyone should recommend lightly. It really comes down to how much those other issues bother you? They are not really bad ones, so it isn't a case of a revision being essential.
If I were you I would still go and see yet more jaw surgeons (or try and get free opinions through email for those that will do that - possibly even with international surgeons). If almost all of them are saying no to a genio alone then I think you have to conclude there is good reason for this. One question to ask all of them is what they think the risk might be of any ptosis of the chin muscle following a reverse SG. It's a consideration. I have some sagging in my mentalis muscle (not from surgery though) and it really bothers me. There is a procedure that exists to excise the excess tissue, but it creates a scar under the chin and may not completely tighten things up (in my case).