You're correct that if related to the original procedure and not performed in the OR, these would not be payable if performed by the same surgeon who did the original procedure. There may be some grey area here to work with, for example if these procedures are required due to an underlying condition that is causing the wound to not heal properly, in which case a 79 modifier might be supported. But I think even in that situation your provider could be taking a risk because a payer audit might disagree and consider it part of the post-operative care and it could be difficult to fight.
In my experience, if a surgical wound is not healing normally or correctly and requires a different course of treatment, surgeons will often refer the case to a wound care clinic for specialized care rather than taking it on themselves since it could involve significant costs that could potentially not be recovered - that might be an option for your physician to consider.