If the bike is tuned properly, fully seating the air screws will stall the bike. On mine, just fully seating one screw will make it very rough and almost die. Seating a second will kill the idle. When the mixture screws have little to no effect, something else is wrong... like idling on the main circuit, or a bad vac leak, or a sync that is far off.
On the most recent rejet project, on a standard KZ550 (TK22's), running pods and Mac 4-into-1, we ended up using the stock jets, and simply shimmed the needle precisely. We used 0.63mm shims with .028" guitar string spacers. This allowed us to use the stock 92 mains, and the stock 32 pilots, and stock needles.
Have you read my site about the imitation factory needles? They end up way too rich at all clip positions, and are not really usable. My site has details on how to identify them. We initially had them and it was baffling how adjusting the needle to the leanest setting still made everything way too rich. It wasn't until I measured them that is made sense.
home.comcast.net/~loudgpz/GPZweb/TK22mai...K22threeNeedles.html
home.comcast.net/~loudgpz/GPZweb/TK22mai...TK22rebuildKits.html