i think trans- denotes “change” or “movement”, right? trans-isomers are usually rotated from their cis state, trans-portation moves things between areas, trans-lation changes the language of a text.
all to say, i think the change in and of itself is significant, and not everyone who’s outside the “norm” feels a need to do it. there should probably be another term for that. too bad “heterogendered” conjures the imagery that it does.
You’re right, that’s the more accurate definition. A state of change, moving from one state of being to a new one.
I think trans still works fine in this context because gender is a cultural label designated to you entirely based on what the doctor thought at the time of your birth and what society assumes from things like secondary sex characteristics and behavior, and the cis label was retroactively applied to describe “anybody who isn’t trans” after the trans label had been in use for decades. So there’s nothing really scientific behind the label beyond the concept of that state of change. Gender itself is a cultural concept instead of a state of being too (as well as a performance that we do every moment of our lives) and so falls more into an active event than a passive state.