So I just tested this idea after bouncing some ideas off of Zeq from a while back. I'm really pleased with this. If you dont want to read, watch the VOD example below.
http://www.twitch.tv/daneywaney/b/621984402Essentially, this eliminates any momentum to a player by sending the player to a box where they cannot move momentarily before returning to the beginning of a jump. So the player would fall straight down with normal speed, as if spawning for the first time. Besides having to make one for every jump, in the eyes of the jumper, the only downside is a black flash on the screen in between being sent back to the start. Watch the VOD for an in-game example too.
To implement into a jump:
1.) Create a secondary info_teleport_destination per jump.
2.) Have your trigger_teleport send you to the secondary destination.
3.) Create a box around the secondary dest. *(See dimension allowances below)*
4.) Place a trigger_teleport below (and possibly above) your secondary dest. inside of the box that will send you to the primary dest. of the jump.
5.) Completely center the secondary dest. model in the box created. In a side view, lower the model so that the bottom is directly above the lower trigger (See picture below)
6.) Find a remote place in the map to place this box.
**The player model size of any TF2 class is 49Lx49Wx83H. The box you create must allow this much free space to avoid getting stuck. If you round up to 50Lx50W, it will be much easier to center the dest. entity in hammer. In my example (See pic from Step 5), I used a box with 50x50x85 HMU of free space for the player. 85 tall because I used two triggers (each 1 HMU tall) lining the top and bottom of the box (Model Height [83] + trigger height [1] + trigger height [1] = 85).
Hope this helps. Ideas more than welcome.
-Dane