If you're happy with the way the bike runs, what's the problem? The spread in your numbers is normal. For example: The Fullsac Stage I, which is their header pipe, 2" cores in the stock cans, stock air filter, and TTS Mastertune, produces typical numbers in the 92-96HP/108-112TQ range, depending on the Dyno, ambient air conditions, the tune, etc. So proportionally, your numbers are fine. While the K&N air filter is not a bad thing, because it will hold up better to repeated services over time than the stock, washable filter, it did nothing to increase your air flow...or not enough to make a difference. The stock filter is a high flow filter, so unless it was dirty, you gained nothing in terms of increased performance of the motor. The octane booster is a gimick...
You mention that you have Rineharts...slip on mufflers on the stock exhaust header? If you still have the stock header pipe on the bike, you're still running with the Cat in the collector, and that is hurting your performance to some extent.
Tuning a bike for peak numbers just to impress the owner is not a "good" tune for everyday riding. Driveability is more important, and that means smooth throttle response, no popping, no pinging, and the ability for the ECM to adapt to varying fuel quality and riding conditions. If the base tune in the Thundermax is a good one, it should be able to adapt to a difference in fuel quality between 91 Octane and 93 Octane. The Tmax is touted as being able to adapt to SMALL changes in motor changes...like changing the air flow through either an air cleaner or an exhaust swap. More radical changes, like cams...it's iffy whether it will "learn" or not. The Tmax, from what I've read here and elsewhere, is very much dependent on a GOOD basemap as a starting point. That is also true for the stock Dephi ECM and a tuner such as TTS or the HD SE Pro Race Tuner...a good tune with either of those devices will allow the ECM to adapt to changes in the riding environment, fuel quality, etc. This is just my opinion, so take it for what it's worth, which is nothing...but the Tmax would be the last choice on my bike for a number of reasons, the main one being that I am not going to change the ECM that comes on the bike to another brand. Modifying the stock ECM with a device like the TTS is a better solution...again IMO.