Mikey>> Start stops create belt slippage and clutch wear regardless of number/size of belts.
Will have zero direct effect on his auger belt and minimal effect on the drive belt.
A couple of Ariens 1028’s were used hear over the first few storms with no problem. One had a ground speed of .8mph. For full bucket clearing of tough conditions the drive had to be worked to let it gather and toss at an acceptable distance. Otherwise the engine would just sag heavily, toss poorly and if continued would just stretch out the belt. That would be over driving the machine.
>>>Suggesting 1/2 cut at higher speeds to me doesn't mean equal performance.
But it will let you use your machine and not have to replace belts.
>>>despite several trips to a dealer for adjustments. Looks to me like the auger belt is stretched out.
Sounds like after several trips to the dealer you not sure about the belt. How can that be? After several trips to the dealer they and you are not sure about the condition of the belt?
A properly fitted belt should be fine and last for a number of years with proper use. It would be pretty easy to nuke a belt with a 10 or 11hp though. A dual system would prolong the belt life but >>>it should have zero effect on performance in the short term<<<. My machines if overloaded will just sag through their power range until they buck and stall without slipping. Going to two or several belts won’t make any difference in performance on you next trip out over a properly fitted single belt.
You can run you 11hp into the ground by overtaxing it, stretch belts and degrade the engine life and be wicked unhappy with your machine or back off, let it take in what it can toss at 25-45 feet and be much happier.