I bedded and floated the barrel on my Remington Ultimate Muzzleloader.
I originally worked up my loads with the ramrod out of the rifle. (I used the recommended Rem 250 gr sabot bullet with triple seven pellets) I put the ramrod in the rifle much later on and discovered that it changed the group size and POI so I left it out. I carry a backpack so it is no big deal to pull it from pack should I need to reload in the field.
After a successful first elk hunt with it last year, I upgraded the rifle with a timney trigger, an arrowhead breech plug and switched to Blackhorn 209 and 300 gr Thor Hammer bullets. BUT first I had my gunsmith bed and float the rifle AND fill in the ramrod groove. He did a fantastic job matching the gray laminate.
I cannot answer if the bedding job changed the accuracy. BUT I can tell you that I had to frequently check the action screw tension with that unbedded laminate stock. I believe the wood was compressing. I encountered another shooter with same rifle and a laminate and he had the same issue. After bedding the action screw's tension remains the same after many firings. If for no other reason bedding would be a good idea.