Too bad they took the approach they did.
It would drive me nuts to find something like that. Its bad enough trying to fix the things that the PO's PO did without have a professional company doing oddball things.
In looking at pictures of how others have installed some aftermarket pumps or alternators, I've wondered the impacts to the belts and bearings on something mounted fixed to a bulkhead or stringer but running off the engine. I would think that even if the belt is perfectly aligned, its still got to absorb all the vibration from the engine moving on its mounts but being attached to the fixed spot...
I have drivesavers on both of my drivetrains, and have been researching them and engine/shaft alignment as I need to replace all of my engine mounts and will need to touch all of those pieces.
Everything I've read is the place where changes are made regarding the addition or subtraction of drivesavers is NOT the engine location - its the shaft. (I'm guessing that's because most engines are fairly fixed fore and aft?) I don't think my Lehmans have 3/8 or 1/2 of fore-aft movement available in the motor mounts, but I could be wrong since I haven't taken them apart yet.
You would think that if they had a new shaft made to eliminate a drivesaver that would have made it a length to mate up to the transmission output without having to actually move the engine back.
Are you going to eliminate the other shaft saver, add one back, or let it ride?
BTW -
yay on you for getting another one of those survey work list issues taken care of. I know our surveyors don't always document everything, or correctly, but for some reason I like to have the goal of reducing or eliminating every finding.