This is a problem I've never really been directly impacted by... I've certainly added pockets before, typically for hanging in a show, but I make my quilts to be washed and I have been asked to help with hanging solutions before.
I would add a pocket if the quilt is going to be hung up, it will give other options than the clamps should the decor or location change. It won't hurt anything to have the pocket being there unused.
I would suggest instead of a continuous one that you split it into a couple sections so that middle supports can be added, wall studs are commonly spaced 16" apart but where that is in relation to the wall and the quilt may not be so ideal. So I'd think about 3 segments maybe? One in the middle with a reasonably large gap on either side and one on each end.