Yeah, polulu 5v step down is probably the best a way to do it, but that means that i'll need to redesign my pcb with inner slot with polulu reg dimensions and use Castellated Mounting Holes for 'docking'.
Was hoping to find a simple way for powering FC and RX from board, if possible.
I'll be receiving first prototypes soon so i'll be able to show what I'm working on. The nature of the solution is such that user would greatly benefit by having inner FC/rx powering
Edit;
worth mentioning, it's nothing complex or complicated, quite the opposite. It's what it does for the user, not about the pcb it self.