I'm a fan of using all the usual specified steps starting with finding the belt's tight spot by using the 10-pound belt tension gauge and checking several spots in the belt's rotation. By finding the tight spot and using it as your test point, it's easy to set belt tension. And obviously the belt tension will mostly be running looser than spec. But not loose enough to skip teeth or whine / squeal from under-engagement. And I never need to treat the belt to silence it.
So my generic take-away from this conversation is that i agree loose is better than tight. And heck, a little looser is better than even a little tight (as evidenced by spec to find the tight spot first). And it seems to hold true for most every belt driven mc, and for most industrial machinery. Go figure.
I guess I think that even though sometimes the manufacturers don't know what's best on this bike (like tires and oil filters and several other things), I think mc and belt manufacturers know more about belt drives than we do.
I can't count the number of members here who suffered bearing failures and middle drive failures because their belt was a little too tight. Fewer have ruined belts or pulley teeth from being too loose. But both failures are expensive and both ruin a good day of riding. All for lack of a $30 mc belt tension gauge.
So why not go ahead and use a gauge and follow spec like the real bike and machinery professionals?
Adding: alignment of the rear wheel so the rear pulley is in line with the drive belt is the other critical step discussed the the service manual and in the pdf linked above. When it's aligned and tensioned correctly, it's possible to remove the rear wheel without touching the tensioning blocks. But if the tensioning block(s) are not correctly set then it's necessary to align while tensioning. Also, tensioning blocks need to be matched pairs and made for specs on this beast. Notice the left and right graduated puller blocks have different part numbers and each is made to fit it's side. If not correct, then you can't trust the graduated alignment marks are physically a matching pair. Bad alignment makes noise and wears the belt edge hard against the rear pulley flange. Belts will by nature run near, or soft against, the rear pulley flange. And a little marking of the belt edge is normal. The matching graduated puller block pair, the axle and fasteners, and the belt tension procedure all work together. Once it's all golden, it's rare you'll need to align as long as you don't need to disturb the tensioning block adjusting nuts.
Puller Blocks:
Left 5PX-25388-00
Right 5PX-25389-00
When held in place it's clear which goes where. In stock arrangement, the left side block is notched to accommodate the axle's head. The right side block is flat to allow tightening the nut.