I'm not going to guess on if they can handle it. I wouldn't know.
I would suggest causing the motor to (near) stall and seeing how high the current draw is, with the boards disconnected.
I would install fuses inline, to protect the board.
You can upgrade the board for higher current motors, or use a special G gauge version. I have one on order for a year and a half now. I think they forgot me!
I sent you an email.