Since Mark and I sometimes share a brain....
@highup rebonds for double glue are kind of dicey. There are a couple out there but the trouble is getting one dense enough as opposed to a slab rubber. We handled a rebond for a while that could be used for doublebond installations but we had mixed results. If the application had rolling loads (like a funeral home for example) it would just cause the pad to delaminate and eventually you'd start seeing wrinkles in the carpet where it had released. In a lighter application they were fine, but if I'm making the recommendation it's going to be slab rubber pad over a rebond all day.