I think most cis people don’t think much about their gender

Of the 5 guys I'm closest to, I think three do seem to clearly value their masculinity. They express it in different ways and I don't think they conceptualize it the same way trans people do and some of them probably don't realize they do care about it.

I tend to think gender is not just BS even if there are arbitrary elements, and I increasingly believe my gender identity ties into my biology in ways that make my gender not a choice but an immutable part of who I am

I don't disagree. My choice of "feel like" was intend to differentiate it from my beliefs and to avoid implying I was saying other ought to feel/think the same. I largely believe my negative feelings towards gender are likely a result of the gendered expectations pushed onto me because of my AGAB. At the very least, I do believe we need to abolish the prescriptive nature of gender.

regardless, I would think a major reason to not date cis people is that they don’t understand our experiences - it’s interesting that didn’t come up for you, but maybe that’s because you don’t date or have sex

That's pretty much what I meant by saying I wouldn't jive with them. I don't think they need to be trans to understand though, but I don't feel like those who strongly feel their AGAB could relate.