There is another way which i used once before in my
sg_platforms map for CSS. This is by using landmarks. Landmarks for teleporters are exactly the same as a landmark for the nextmap does in singleplayer. it remembers your position when you hit the trigger and places you on the same place from the landmark. This allows you to quickly have alot of players entering the same teleport and all have the same position as when they ran in.
The only things you have to do is make a info_landmark in the center of the teleport entrance and give that entity in the landmark value of the teleport trigger. (im not sure if the exit also needs one as the last time i have watched the vmf file was months ago - i can still check it if you need)
I dont know if this works for TF2 (and if its the thing you ment) but if you want it like that its worth to try.
Still, this way has 1 downside. landmarks make it impossible for you to rotate the player (at least, i wasnt able to). But if they run in the teleport backward they come out backward also.