I dont. I use my frame pack all the time. If I take my bag off the frame I will strap a small bag to the frame. I do have a small daypack (internal frame) for fall time black bear hunting. It will carry the hide and it doesnt snag on alders or whatever.
I've wanted to use like a daypack for all around hunting but I hate to go back to camp to get the frame pack when something is on the ground. especially sheep or goat hunting and camp is at the bottom of the hill.
I use an Epiards lounge turkey vest.It has a metal frame which serves as a chair when sitting [imagine a capital Letter L pointing left,that's the shape of the frame against your back],lots of pockets,and a big waterproof game bag on the back for hauling extra clothing,etc.Works for me,and gives me real comfortable back support,which helps stabilize off hand shots.