If you're eventually going to cover it with drywall or T&G, I wouldn't go to the trouble of adding any additional layers of scrim paper or anything....
If it's not dried, stack and sticker where there is good prevailing air movement with just a cover on top so that precipitation doesn't stand on top...
"Technically" the faced fiberglass needs to be covered due to fire risk, so I'm glad you intend to do that with the 'rock or T&G. You might consider...
Benchtop could be useful but not as useful as a floorstanding. I watched a video from Bent on youtube this morning he was complaining that he bought...