Yeah it's uncomfortable as hell to sit with anything in back pockets. I've actually utilized this at work. My customers often have me sign out contractor keys that I must return before leaving. Keeping them in a back pocket prevents me from driving away with them. I'll know as soon as I sit down if I didn't return them

I clip my work knife in my back pocket that is on the far side distal. It's in a good spot that doesn't interfere with sitting.

My folding boxcutter has a belt clip and I hang my Gerber Dime on a suspension clip. Both live at the top of my rear pockets. I never sit on them.