This has already been asked before probably but if not... I was thinking for the gender locked IFs you're brainstorming, will mc identify differently only in their head? I can't imagine the cast in either of them respecting MC's pronouns. I'm assuming that regardless of how they identify the ottoman MC will be referred to as a woman and is AFAB and the WWI? MC will be referred to as a man and locked to AMAB because in militaries they have physicals.
I’m not writing a WWI if
They will be referred to as their assigned gender
They can ask their ROs and loved ones to refer to them a specific way in private. Although the war if mc has more chances of being able to actually live out their trans life when they get back home. There were openly trans people out in the 70s