If Cy's the trans one, I think his parents would be mostly OK with it because they both wanted a son, so in a way it's like they're getting their wish. For Lynn/Eden, transfem or transmasc, I think their parents would chalk it up to a trauma response from The Incident and let it slide because they love their only child so much, even if they're not necessarily comfortable with transness.

Cy's tall as shit, so even with the same starting point as Lynn, he'd be taller, but only by a few inches (he'd probably be like. 5'11 instead of 6'3). He'd also likely be more athletic than canon Cy to try and compensate for his dysphoria, so while he would be at a disadvantage against his own canon self, he could still break Lynn in half.

Yup, he's got a bunch of different strap-ons, ranging from super realistic prosthetics to very porny fantasy dicks!

Cockblocked by dysphoria this man will have to express his sexual fantasies for teenage girls through cringey roleplay with his wife 😔

I think he could potentially get bottom surgery, but only as an older man, cause he would not be satisfied with the phallo results available in his youth. As for Lynn... It really depends on how their kink life evolves, but leaning towards "no".

I mean I have drawn trans guy Cy stuff before, and while he definitely wouldn't be as much of a fiend as canon Cy (tfw dysphoria makes you reluctant to groom teens 😔) I feel like he'd definitely fit in my series of "realistic alternate Cys". I think being exposed to Cy and his transness early on would probably make Lynn more open to the idea of dating a trans man than canon Lynn, but your "yay liberal points" guess is right on the money, she 100% would internally congratulate herself for that. Overall, I still think they'd have a pretty good sex life, but Cy would undeniably be a huge stone top, and it'd probably take fucking decades of being together for him to let Lynn touch his genitals directly, cuz I think his dysphoria would be absolutely hellish.