I don't think that there is a discord right now but feel free to start one. I'm not to sure about the retry skip my self.
Hey, I coined the term so I may as well explain what it is:
The checkpoints and respawn points in the game are all triggered by large boxes to ensure the player hits them. These triggers are ¤far¤ bigger than they need to be and extend far before the respawn points. Because Retry-ing a level places you at the last triggered respawn point and is instant, it technically means time can be saved by selecting Retry from the menu as soon as the trigger is hit to save a few seconds per level by skipping small distances or jumps by clipping the trigger and then immediately selecting Retry.
I don't think so. I was planning on using the editor to look for optimal places tonight, though.