Either way, I can probably do something hacky like use the heavy weapons team entrenchment ability as a scaffold for transforming a land unit into a flying unit and back again. I gather I'll be abusing things like that to smash together the functionality I want haha
Not sure you can, the entrenched unit has to be static. Possession might work, or you use could SCAR and swap it out. Neither will be perfect, but what is, in dow?