I think idea of setting brakes that you mostly don't lock them up came to simracing when pedalsets had simple pots and short range, so idea was to set brakes so that you don't need to modulate brake pressure you did set so that it almost locks up. Also brake pedal springs were pretty weak in force. With real cars though you can lock up brakes quite well if pushing enough hard, well many of them at least, can't say too much about high downforce cars. Brake force is usually calculated in sims with something like 80kgf on brake pedal, which might or might not be accurate to person in question. I did 1 leg squats with 60kg additional weight, that was 160kg on one leg which for example might be deviation from the norm (would be interesting to know what amount of force real racing drivers are putting on brake pedal), but that was when my knees were not busted from other reasons, anyway I'm just pointing out that for me 100% brake pressure may or may not be accurate. Also there is an effect with braking as g-forces help you push the pedal, actual 100% might or might not be higher than what is currently set. What OP is experiencing might not be completely related to that 95% instead of 100% but also some effect might be regarding simracing type of brake force setup. For example putting considerable more brake pressure on brake pedal might or might not be realistically achievable. I simply don't know if 80kgf on pedal is value used to get brake forces at 100% brake pressure, if it is, then 100% pressure might not be giving quite the excepted braking force.