I also changed my kymco rolls to dr. pulleys sliding rolls (13g) today and sliding pieces. And I also cleanded the clutch and bell.
The sliding rolls performance is extremly smooth and remarkably improved compared to the original ones.
But I now also have some temporary vibrations on take off. But only when taking off very slowly and gently with a minimum amout of throttle (snail take off). It´s a Kymco clutch issue I guess. When I open the throttle a little more and quicker on take off, I don´t have the vibrations, because the clutch then locks faster.
Just adapt your driving style on take off. You will get used to it. And by the way it´s more fun, because you might leave some other riders and drivers behind you.
Or buy a HIT Clutch.