Belly sleeping six months

So, my baby is 6 months old and has been rolling both ways since 4 months old. He rolls himself all over the house. But when he sleeps ive always put him on his back and then often times he rolls onto his belly to sleep which is safe as I understand since he did it himself. When he goes down for naps, I put him down either fully asleep or mostly asleep on his back. If he is fully asleep he usually stays sleeping on his back but if he’s mostly asleep then as soon as he touches the mattress he flips himself onto his belly and goes to sleep and he always sleeps way better. He will move around during nap and go back to sleep and sleep 1-3 hours for naps but when I put him down and he stays on his back he wakes fully every time at the half an hour mark and is done with nap. Is it considered only safe sleep to always lay them on their back through a year even when they’re “belly sleepers” and have all the head control? I’ll continue to always lay him on his back and deal with the short naps if it’s considered safer, it just seems silly sometimes when he can roll himself and sleeps better when he does.