I did a PM&S-24. Our residency program was restructured the year I entered.
Ideally, residencies should be standardized to 3 years and lead to same certificate. That's not what happens now. Yes, they're all 3 years, but some 3 years lead to certification in foot surgery and others lead to an additional RRA certificate. How stupid. And it still perpetuates this ridiculous dichotomy in podiatry creating that Mason-Dixon line across the foot, dividing it into forefoot or rearfoot and ankle. (PS what would you think of hand surgeons self-discriminating into metacarpal and phalange surgeons or carpal and wrist surgeons?)
In your scenario, you get a certificate in foot surgery whether you leave after 2 years and take a PMS-24 or you stay an extra year and do a PMS. If you're comfortable, it makes no sense to stay. I don't think that fact alone will impact your future practice, prestige, or income potential.