Hammock under quilt as top quilt?

[beaudetious]

I have recently converted from hammocking to ultralightweight tenting. I would like to use my hammock's underquilt as my top quilt now. It has no footbox though. It's rated for 20 degrees and the temps for my upcoming hike probably won't dip below mid-30's. Also, it's super lightweight compared to my normal 40 degree sleeping bag.

Is this a disaster-in-the-making or a good idea?