Medical transition is a whole separate hemisphere of trans life. Despite what most media depictions imply, the majority of trans folk never pursue surgery. Trans folk have always existed, long before medical options were possible. It's even more recent for them being wildly available. I think most of the community would agree that transition begins when you decide to start pursuing something else, not necessarily after egg crack/coming out/hormones/surgery.

He refused with disgust while counter questioning - "Would that make me more trans?"

Well... good! I am super happy for him! It would be far worse if he felt he had get surgery since that means he'd been suffering.

Honestly this isn't unusual. I myself did only social transition before deciding ~6 months later to start HRT. Fundamentally he is on a super healthy wave length. We can't always control how the world perceives us, but so long as you know yourself and are supported by the people who matter, then everything else is just noise.

Transition is all about finding a better way to exist, if he doesn't feel the need to do any sort of physical changes, that is great! If he changes his mind someday, also great! That day never comes? Still great! The reality of transition is baby steps into something new, then stopping to reflect on if that helped. Him coming out to you sounds like one of those steps. Up to him to decide the one after that. There truly is no wrong answer.

Since you already talking about medical transition, I think you should make it clear that if he does decide to do that, you'll support him. And then never bring it up again. He knows its an option but you don't want him to feel like it is an expectation. It's not for everybody and surgery itself is in no way a reflection of "how trans you are". We're all different.