This directional sound issue is really frustrating.
I don't think it will be solved with substituting the enemy jumping/landing/footstep sounds. The sound itself is fine, the problem is with the direction you're facing relevant to the enemy. If he is somewhat behind you, you can't hear them. The levels for the same jumping/movement sound is completely different if the enemy is few "meters" in front of you vs behind you.
I have the same story as u/nonstickswag I'm playing with a group of old quake veterans, everyone has pointed this out. It's quite obvious...
Also, if PnCr and shaft are supposed to give the enemy warning like it was in quake, you'll need to increase the amplitude radius of those sounds. You have to stand right on top of the guy to be within in the radius for the sound.