I don't understand it, why do all this to a bike, unless it's been buggered and your putting it back to original. The only thing I have ever changed on a bike is a taller screen on the 600. It has the spoiler attachment so cuts down buffeting at speed. All the tuning, etc, would have been done to optimise the settings, and the exhaust made for the bike. Why buy something, then spend even more money and time altering it. I would not buy a bike if it did not suit me or not do as advertised, I'd walk away, not buy it then spend more on it getting it retuned/mapped.
I did, in the early eighties, strip my 125 to change the rings, but then decided to see what could be done to increase performance., and ended up gas flowing the ports, skimmed a few thou off the head and thinner head gasket, flat headed piston with deeper grooves so valves not hit and other bits and bobs. Bike ended up 12bhp above standard, and after running everything in I took it to a long straight road for a speed test. Original top speed was about 88mph. I passed that at about two thirds throttle, kept going until I hit a indicated 104mph then had to back off, I hit bad steering wobble.
As the bike was not meant for that speed the tyres were not rated that high. The Avon Road runners I had were maybe only meant for 90 tops, so never found out what it could do.
Incidentally I ended up crashing big time on black ice on way to work so bike was a write off