I've always stuck with specs .. better safe than sorry !
Totally understand your position.
But I can give you one factory spec I know can be better. Belt tension. If your rear swing arm bushings are in good shape, belt tension as defined in the service manual is way to tight for my liking. A 1/4" of deflection with 10 lbs of pressure is crazy tight once the bike gets to operating temp. I have been running much less tension since day 1 of ownership and have
never looked back. The bike feels so much better. So much more relaxed. My belt tracking is better, belt noise is 100% less, no more rear pulley wear like I had... It seems like everything is better.
If you look at the arc geometry of the rear swing arm, you will see why I believe this. It does not follow a constant radius. The belt gets tighten, the lower the frame sits. So under certain conditions, belt tension actually supports some of the bikes weight which it should
not do.
Now this applies to my Dyna and I don't know if it hold true for other frames.
If the Moco wants it a certain way, that's fine. That's what makes America beautiful. I will be the first to say I am wrong if & when the day comes. But so far for me, I feel my way is better.