Do you still have your shaft alternator. I always switch mine on when sailing. It keeps the batteries fully charged. When you turn the key on the 12v panel there is a very significant drop in the propellor speed.
I have not noticed any problem with wear on the shaft wearing out bearing either.
Before putting the engine back on I always put the gear lever into reverse to stop the prop shaft alternator charging. I don’t think this is a big problem, but it was what Amel recommended.
Ocean Hobo SN96