I can't answer to your question specifically. I do want to say that I have always pumped. I am uncircumcised. I had a
Hyaluronic Acid injection done. Pumping afterwards would stretch the skin a lot. not a good result because it's permanent. I assume you are cumrcumcised. and you pump with
PMMA. it would add volume and water retention in the skin and between the skin and shaft. You would definitely get stretch marks, bruises, and extra skin after some time. i don't know what it would do to collagen production. my two cents on the topic.