I'm trying to get my head around fitting an underquilt to my flex to cover me and my girlfriend ive seen the settups by keith hubble and quiet, i really like the velcro on the top edge however when we sleep in it our heads are usually a long way down from that more level with the vertical part of zippers so i would be wasting a lot of quilt length above our heads. Has any one been 2up in a flex and used UQ's any advise would be appriciated.