A wallpaper seam roller works just fine as long as it's heavy enough to put a bit of pressure on it. It also helps to roll up the patch from the outside edges, makes the contact easier to control since, as you said, once it touches, it ain't moving. Make sure that you don't leave any air pockets.

Oh, work in a ventilated space. Contact Adhesive and raft cleaner isn't good for the brain cells and I don't have many left to spare after a misspent youth.