Hey. I know that usually in demos for episode one, the bunnyhopping will cause the demo to be jittery as hell. In the HL2 run, everyone could just lower cl_interp so it looked okay. However, in EP1, cl_interp is fixed and you can’t change it.
However, cl_interp is calculated by cl_interp_ratio / cl_updaterate, both of which CAN be changed. By using the minimum value of interp ratio and maximum value of update rate, you can lower the interp dramatically.
The minimum value of cl_interp_ratio is 0.1
The maximum value of cl_updaterate is 60.
Using both of these, you can get an interp of 0.017. Not as low as was used for HL2, but still EASILY enough to dramatically reduce the amount of jitter from bunnyhopping.
The only trouble is that NPCs look crap while this is in effect. I imagine that if someone wanted to do a recording of this, it’d be best to have a bind between each one, so that as soon as you have to stop bunnyhopping and pay attention to an NPC, you just press the bind and everything looks fine again. Start bunnyhopping, press the bind again and you’re sorted.I made an example bind for this:
alias interpchange "interpchange1"
alias interpchange1 "cl_interp_ratio 1; cl_updaterate 60; alias interpchange interpchange2"
alias interpchange2 "cl_interp_ratio 2; cl_updaterate 20; alias interpchange interpchange1"
bind p "interpchange"
This means that on every press of p, it will switch to the opposite of what you already have (Apart from the first press, as it uses that to just set it up for bunnyhopping)
This may be complete rambling, but I hope everyone who cares finds this useful 
EDIT: Looking back, after some more runs, this method isn’t that amazing, but I think it’s still slightly useful. We might be able to expand on it.