While, it is known that almost every choice we make when introducing our reject to the warband has no or very small changes.
The main exception to this is when picking our characters size. Making a smaller character will actually help you avoid ranged attacks by making cover more effective.
I would love to see a set of very small bonuses based off the lore/backstory of our choices. Like making your character bigger could give you a small increase in you toughness. Or having a small bonus to revive speed if your veteran character was “saved by Sarge” so on and so forth