EDIT: this tech between Wrecking Ball and Symmetra's Teleporter has been considered a "bug" by the Overwatch Team and they fixed it unfortanetely. (see patch note from 08/04/2020)
This is a workshop mode I created to practice the trebuchet tech invented by Dyslexia. You've probably heard about it in NoobHunter's videos (see for example these clips from Jay3: https://clips.twitch.tv/SpineyBombasticBearBCWarrior or https://clips.twitch.tv/TriumphantBrainyPigeonOMGScoots)
So how does the trebuchet tech work?
1) before any grapple use and after each jump trial, use the teleporters at least one time by just passing through one of them.
2) hook your grapple on a distant surface (the longer the grapple is, the higher will be your take-off)
3) roll fast to the teleporter from which you want to take-off
4) release your grapple as soon as you enter the teleporter (after pressing the 'F' key, to "interact" with it)
In this workshop mode, your 2nd ability, "Adaptive Shield" (your 'E' ability on PC), has been replaced by Symmetra's teleporters who is an invisible ghost following you with the sole purpose of spawning TPs on-demand :-D
The goal of this workshop was for me to be able to test this new tech without having to find somebody to play Symmetra for me and ask for teleporters everytime. Here's an example of what you can do =>
I'm an amateur, it's far from perfect in terms of coding and practicability, because, for example, we cannot see how the teleporter is being placed like a normal Symmetra would be able to. For now, you have to aim your reticle approximately to where you want your teleporter to be located and press E to spawn it. Press E a second time to remove both teleporters. Et voilà!
If you find any bugs with my workshop mode, please let me know in the comments section.
I would like to get rid of Symmetra's voice, but I think it's not possible. Maybe I will add a virtual sphere on the reticle so we can better visualize where the TP spawns, but as-is now, it's pretty simple for me and "it just works" ;-)
Feel free to practice the trebuchet tech on different maps and have fun!