Experiences with Ivan Kit

[dueruote]

I'm not the OP but since OP's issue had been addressed, it still looked adequate to follow up given the thread theme.

I'm not complaining the bike has too much power, just wish it could be a bit softer in its delivery in the lower and mid range.
I have installed the slip on version of the kit and I  have also an Akrapovic slip on, but not the full exhaust.

By the way, I have drilled both bypass holes. 
At the time these were the most widespread instructions or perhaps I missed the feedback of drilling only one.
Is it a big issue ?  Could the engine run too rich with two enlarged bypass holes ?

In the end, I much prefer the engine as it is now with the kit.
I'm just talking about fine tuning, but no way I wanted to go back to how it was before.

Thanks !!