quick shifter?
no good idea
if you can´t adjust it super perfectly and if you don't shift (up) consistently
the "timing - delay" should be around 50-60 milli seconds for the gear blocks to get into the gear notches
and if not adjusted perfectly,
this, we all here suppose,
will be the consequences to the transmission / gearbox
and the expected material costs to fix the trans alone will easily reach 1,000 €
(issue was never more reachable 2nd(+1st) and 6th gears - only shiftable up from 3rd till 5th and down)
my serious and personally hint was to leave the shifter in its shiping box,
if it is no "Tellert".
(the tellert is adjustable and won´t destroy your gear wheel´s blocks and notches)
that´s what i learned from a german graduated craftsman (master craftsman) by his video at youtube.
and if you wanna be lazy and don´t wanna use the clutch lever sell the busa and get a bike with automatc transmission/gearbox.