Hey, good run, lots of fun to watch, and some tricks I didn't know about, but there are some tricks you didn't utilize, too, that I figured I should tell you about.
If you use controls setup B, where you control Shaggy with the D pad (it's actually far superior for RTA runs, because the camera doesn't fuck your controls up so bad), and hold forward, and very fast afterwards press and hold a direction (it might be one frame, but idk the timing is pretty loose on console), Shaggy does a "doopwalk" where he walks forward while turning. For one, it's hilarious looking, and it's useful for RTA runs, but also it appears to make Scoobyboosting more effective.
It was actually from doopwalking that I discovered Scoobyboosting, because it makes you go so much faster, for such a long period of time. It's funny that you discovered the same trick through different methods, and named it the same thing.
Anyways, it's funny that you uploaded this, because it was actually the first TAS I was intending to do. I really enjoyed your run, and I hope this helps c: