The email template speedrun.com uses is so awfully out of date it says "© 2017".
I'm sorry for the late reply but yeah sadly we don't have a wiki / discord. If you wanna set up a discord and be willing to maintain it I could certainly help you out with various tricks.
Some quick primers that can be hard to find: ¤ Jumping is faster than walking, but sliding on the edge of platforms can be even faster. This requires you to balance on a narrow ledge though so most of the time it's not worth the risk of dying and losing a lot of time. ¤ The game runs at 30 ticks per second, one of the artifacts from that is that when you go on a boost ramp you have 1 tick to jump off that boost pad before it takes control away from you. This is exploited in C-6 to do the level in either one or zero button presses (if you opt to not spin the platform you'll want to jump around it as you hit it). ¤ Given the right angle the game will attempt to align you to a platform. At near 45 degree angles however we're capable of sliding up "walls" and landing safely on "floors". This is abused in D-3. ¤ The buffered jump you can do in mid-air with speedrunner mode enabled could use some extra description. Any time you take a "step" you're allowed to jump once, even if you're in mid-air. Steps are normally gotten from platforms but can be achieved on top of buttons and on the side of platforms, even though you can't safely stand on these.