All gears are undrcut to a degree on all modern bikes. that is why you can shift with no clutch. This is even more for high performance and using over Drive gearing. Thats why i am checking, i am not sure of the advantages either yet.
I had a 2000 GSXR 750, and of course like most gsxr750's made that year, I had second gear slippage. this meant under hard acceleration, once I'd hit about 10,000rpms in second gear my tranny would slip. Basically it was like chopping the throttle really hard and fast 2 or 3 times. The first time it happened it almost killed me.
After I got the tranny undercut, I noticed a HUGE difference. The bike shifted much easier and smoother (if that is even possible on a suzuki), it would just gently click into gear, it was amazing. I think it cost me about $400 to do all 6 gears, even though you only really need 2nd (and I think 6th), plus about $200 in labor (I paid a motorcycle mechanic to do it on the side, thanks Larry @ Broward Motorsports!
. It took about a month, and it was a major pain in the ass.
If your transmission works fine, dont even attempt it. Unless you are experiencing transmission slippage, or planning on upgrading to a 400+hp engine, I wouldnt recommend it at all. It is an incredible amount of work, and unless it's broken, it's not worth it. Just my opinion