I am hoping the larger bb's will roll over the ribs better than the small ones.
As for tires on the HF tire changer, The bigger tires are easier to work with. All tires need some good lube to mount and dismount any time you do it. My 235 85 16 truck tires are a snap on the HF changer with good lube. I run 25-30% dish soap in water and it works great. The smaller car tires are harder to do, but not real bad. I just changed out 7 truck tires 2 days ago in no time. The hardest part was lifting the 75+lb beasts onto the changer.
I have it bolted to a pallet to make it portable and that is awesome.