I have an HMF dual low-mount that I just installed.
After taking it on a short test ride with the stock map, I loaded the closest map I could find: the high mount version of the same exhaust. I figured the only difference is a couple inches of mid-pipe length.
The bike ran super strong! Pulled much harder than oem or piped with oem map. Second gear power wheelies (tucked in) at 80-90 mph, brought up front wheel again on hard shift to third at over 100 mph.
I suggest trying a map from a pipe that has the same configuration. In other words, if your pipe is a true 4:1, look for a map for another mfg's 4:1; if yours is a 4:2:1, look for a map for that.
Naturally, a custom tune is the best way to go. With the difference I feel seat-of-the-pants, I probably won't pop a few hundred bucks for this, but I want to put some miles on this combo to see if any flat spots are evident and also check fuel mileage.
Maybe the map you used (that is supposed to be correct) has some kind of subtle file corruption.
Good luck,
Blue