KRK is a problem for direct turnaround. KL always uses a bus gate at KRK and usually the gate is already closing by the time the you disembark.
I would advise you to start at KRK and assuming it's an xp run - do your immediate turnaround at MAD since you disembark the aircraft directly to the line of people waiting to board the next flight at the same gate. I
t's better to overnight at KRK anyway since there's a cheap hilton at the terminal and you can time your check-out exactly an hour before departure and still have plenty of time for a quick coffee at the lounge.