Here's an idea: Add a trigger_hurt (or whatever you use to kill players that fall off) that goes along the cliffside. I don't like when I die on the way down from somewhere, but if I hit something along the way (ie a cliffside), it makes sense.
I can't say anything else right now because I haven't tried it yet. Is it just me, or hasn't there been a Gameday for quite some time? =(
Why not.... a playerclip?