Hi Eric,
I don't understand!?
There are no problems at all, no matter if you've checked or unchecked "Run in a window", "Start out maximised" or switch to "Full Screen" in the engine window" - in all cases the dot/hand is positioned correctly on the board.
The scaling (also for the claw) is done automatically by MAME whenever the window size or position is changed in any way.
Regards,
Franz