how to make cot comfier

my 12/13 year old dog sleeps on a cot as his bed for a few reasons. i have a dog that likes to chew up dog beds when a door is left open or when left alone. i live with my family and sometimes they leave the bedroom door open by accident. not a big deal, but we’ve been through a lot of beds and ever since the dog beds were replaced with cots, destroying beds hasn’t been a problem as all beds are non existent. however, my oldest dog loved his dog bed (it was the only one we found that he genuinely liked and layed in without forcing) and he doesn’t love the cot nearly as much. currently there’s a comforter on the cot with a fitted sheet over the comforter. any suggestions to make the cot more comfortable without foam/stuffing or another dog bed? thank you!

we did have his old dog bed on the cot and that worked, until the bed was chewed up. his bed was the orthopedic furhaven chaise bed.