www.nhs.uk/conditions/cosmetic-procedures/cosmetic-surgery/breast-enlargement/The NHS would put a weight based warning on (as they do for other procedures) if there was any issue with being larger and having the procedure.
It makes sense because the area is easily accessible and extra weight couldn't cause access issues.
It might be best to have a convo with your doctor about it.
Thought I'd post that in light of the absence of any response thus far.
