under heavy use, like on a track, brake feel changes. even with racing brake fluid, it changes. that's why there are remote brake lever adjusters on race bikes.
tie your brake lever down every night; it helps squeeze out bubbles that even the most meticulous bleed misses, and minimizes this effect.
but it's something you'll always deal with, no matter how good the brake system is. if the MotoGP guys with their megabuck brake systems are having to adjust their levers due to more "mush" in a 45min race, you'll inevitable have to as well.
2012 S1000RR, sapphire black, DTC and HEATED GRIPS
2014 Ducati Multistrada Granturismo
2011 Ducati Monster 796 ABS
2000 Ducati ST4 (sold)
2010 S1000RR (sold)
2007 F800S (sold)