long term goal is to continue working but need interim extension

Currently on expired non B extension of stay so in amnesty as contract was not renewed after 10 years. Not desperate enough to accept primary school teaching which is all I have been offered.

I was told I need a foot surgery  back in February (and have followup with Dr this weekend) which I was hoping to do much later but it would be a valid reason for medical extension as foot would be in a cast. If I got the medical extension could I switch to new non B in Thailand later?

Or I  qualify for retirement visa but again would want to change in Thailand to new non B later, when I get the job I want. Would this be possible to do in Thailand?

Guessing getting the letter from US Embassy to ask for 30 day extension would not fit with my plans, either.

I want to legally extend my stay but am afraid I would solve the short term problem only to find out I screwed myself based on that decision as some with ME visas have reported.