To prevent the batts from slumping it might be possible to lay precut lengths of backed batt down on precut plastic sheeting. Tape the flange on the batt to the plastic using that foil tape that hvac guys use. Then fold and seal the edges of plastic around the batt using the same tape.
'Sealed'
packs for wall or roof, like in your diagram. No
saturating the batts and no fiberglass decanting onto everything.
packs could be hung, stacked on edge, stuffed above rafters. Easily fit curved surfaces. You know that just might be a real winner for insulating yurts.