Keith;
I've seen that mod before and am inclined to do it when I stop being lazy. A proper hydraulic AP would be good, but my preference for the money would be a wind vane.
Agree re the Raymarine design flaw, and I'm amazed it doesn't come up in online discussions. In all modesty, I can't recall anyone before me highlighting the stall protection issue in any of the discussions I've read. A cheap half-way fix would be a time-out on the motor directional drive signal, so it would only be stalled for a couple of seconds.
Cheers, Graeme