I find out that they are using 25% 33% sizes very often!

Couple years ago i saw that NL HU players were using 25%-33% sizes just On The Flop, now they are using those OTT and OTR as well.
And now SNG HU Top players also using 25%-33% sizes OTT and OTR.
But my question is HOW THE F* THEY ABLE TO RUN SUCH A SIMULATION IN PIOSOLVER?

Let's say we play SNG HU Hyper Turbo (25bb deep) it's a limping pot and we want to have 25%-33% bet sizes OTT and OTR
If we put such digits into programm.. there definetely will be a situation where we didn't CBet on the flop (there will be 40chips in a pot), so as a result then there is no longer will be possible to bet 25% on the turn (because big blind is 20chips), so in this case OTT you can only BET at least 50% of the pot. So all the calculation with 25% turn bets and 25% river bets goes straight to hell. Because now PIO shows me that i could possibly bet 25% OTT and 25% OTR which is not.

My question is:
How to correctly calculate such a situation?
How they doing it?