Well I wasn't imagining it, my bike handles liked crap according to the tech! No compression and can only adjust the sag a couple of mm. No faults flagged so looking to be mechanical. Have a left front fork internal on the way and hopefully that will sort it, only a 3 week wait
Seal replacement was on the right , not much in that side, just a spring and some fluid.They did pull it apart again just incase, but all good on the right.
Had a base 2013 and couldnt get rid of high speed weave. Even after a £650 front end rebuild with cartridge kit and pro set up. Weave was commented on by a guy following on a fireblade during a track day session. Tried different tyres, different settings. No joy.
You stated earlier that you have changed the fork seal twice on the same leg, that's where I would be investigating, if there's something dodgy with the one leg then it's bound to unbalance the bike and even more at high speed. Ask your dealer to change the whole leg for a trial to see if it improves....
They pulled the right leg apart (where seal Was replaced) again just to check all Was good. The right side doesn't do much in the S, don't know about other. There's basically a spring for the preload and some oil.