Cubeorange CAN2 only (mini carrier board)

I have multiple carrier boards, mini and standard.
I have noticed that CAN only works when I use standard carrier board, and not mini carrier board:

I am using 1.12.3 build and I cannot get CAN port to work on the mini-carrier-board.
The board only has CAN2 routed to the connector.

I would like to re-assign pins so CAN1 becomes physical CAN2.
Is this done in board.h or somewhere else ?

Can anyone help?
Current stable version works fine with mini-carrier-board, but I cannot just move, I have some dedicated code running and I must stay on 1.12.3.

Thank You,