Is your PCP willing and able to provide the pain control you need?
And any added paperwork & oversight...
That is the first thing to check on..before you make any changes..

Some states, areas are cracking down on RX meds/controlled meds, so PCP may not want to deal with that if it is - or becomes an issue..

Not an expert in the SSDI stuff, but I'm sure others have change drs over time for various reasons, so as long as all documentation and such is good..I don't think it would be a problem..
Drs retire, move , close a practice...and people need to find a new one..