New 360 character transfer

Question. I’ve transferred my BA rank over and my characters. Everything worked well. What happens in this scenario though.

-Everything has been transferred (as stated above)
-Make a new character on XBox 360 for multiplayer (my friend only has XBox 360)
-Playthrough this character a bit and earn BA rank (as you do with everyone character)

NOW…if I upload this character to my XBox ONE, will it transfer the BA rank I earned. Or should you not be flipping back and forth between 2 systems?

Pretty sure the highest badassrank will always be used on the Xbox one side.