I had a wall quilt that I sprayed and then left for over a year ... it was still well tuck up!
Sometimes as you work with it, it starts to peel a little at the edges, just from all the handling and movement. It hasn't been a problem and hasn't gone too far into the quilt, so I just hold it in place when I get there.
One caution ... remember a little will do a lot ... you don't have to super-coat it in fear that it won't hold!