I'm not sure I necessarily understand your question, but to my knowledge, how you file in 2023 does not affect at all how your payments down the line will be affected. Your income in 2023 will not affect your income recalculation in 2024, etc.
Keep in mind the goal of these repayment programs is not to extract as much money from you as possible, but to charge you an amount that you can reasonably pay. They do not care one bit if you file jointly or separately to affect your loan payments now. From the loan collector's perspective, they are happy to charge you $0 payments for some time (and will offer you this for the beginning of residency).
As I noted above, unless you are 100% doing PSLF, consider that reducing your loan payments does not, in fact, save you money. It just creates a slightly larger bill you will have to pay later.
It is a general statement that you will receive a lot of financial advice over the next few years from colleagues and strangers both, some of which is good and some of which is not. This forum is probably not the best source for financial advice - physicians are notoriously bad with money, and medical students are probably worse. I suggest you run the numbers on many situations (including years down the line) and do some research on your own.