I have the MFW vario pegs, but I have gone down and back, not forward. I did not have to change any components.
The rear brake had enough adjustment (just, I'm tight to the stop), only problem is because the lever is lower, setting the light was a pain.
The gear shift, being lower, made the linkage hit the foot peg hanger, so I used a dremel and cut out the back of the hanger.
Saved my knees!
Don't forget the vario pegs have no rubber and a slimmer so they start 1cm or so lower than standard.