I grew up riding atv's since the first three wheeler days. Always put in the low end 87 and never had any issues. Some of these machines around here have over 50,000 Mi on 87 octane. Yes you read that correctly fifty thousand miles. Lot's of those miles are hauling fish in the sand towing boats etc. Tried higher octane av gas 100 low lead. And octane booster. Never made any difference in work performance, just the wallet lack of performance. However, if you where to put in a higher compression piston, say a 10.5 - 1 or higher You will see a benefit from it. The higher octane, just for lack of better words, keeps the gas more stable under the higher compression to keep it from predetonating. (PINGING)
As to whether it improves perfomance for you just try it out. I will stick with the 87 octane myself until I get my higher compression piston.
GL, Have fun. share your findings!