'brifter' is f'ing stupid
you do know about the 'trim' clicks in your shifter, right? there are half-clicks that don't move enough cable for a shift, but allow the derailleur to be 'trimmed' so it doesn't rub the chain. also, limit screws will never change any shifting problem, if they were properly adjusted from the beginning, they won't change. if something else happens...cable stretch, housing compression, derailleur bent or moved...that has to be addressed. limit screws only do that...they limit the travel of the derailleur, nothing else. the height, and angle of the derailleur itself must be correct and the cable tension must be correct for proper shifting.