no stick, but if i am unsure i use the shaft end of my maglite, recreational fit wants to be less than 20mm so if i can get the head end down there the boot is too dam big, i am pretty good at judging distance with my eyes as it is something i do every day, most fitters on here will be the same, not many of us talk in fingers as they are all different
depends on the person but 5-10mm for racers if the shell shape is very good 10 -15mm for a reasonable skier 20 for a real one week a year don't like tight boots slider....but everyone is different i know racers who will not tolerate anything below 15mm and recreational skiers who like a 10mm shell fit
biggest problem we see is the liner variations from model to model, couple that with the differences in peoples biomechanics and it is a mine field