I had just found this, somehow doesn't register inside the game's mod list. Known issue? Banned due to forbidden knowledge?
Anyhow, your writeup directed me here, thanks for the work!

Cheers! I wouldn't consider the graphs to be particularly cheaty, just that you don't need this much information most of the time - a "peak" value and a "pretty good" range are enough.

Though the real reason why I got around to it is suspecting that things aren't as simple as they seem with tunnel transitions and direction change calculations. And I was right - DirCh/min is a whole thing (with interesting implications for low-velocity rides), and tunnel segments on adjacent track sections count as one, which explains oddities in some of my designs.

I'm amazed someone actually made a mod like this. Having made the coaster stat calculation guide on the fandom wiki, I'm so happy there's now an in-game way of being able to tell how to improve your coaster's stats that doesn't require you to have seen the bezier curves as they can easily feel very cheaty. Even so, having access to said bezier curves can now allow you to properly optimise your coaster to have stats that fit said bezier curves.

Also, thank you for publicly displaying what a direction change actually is. I was stumped with regards to the stat as it seemed to correlate with actual turns when testing it. I found that consecutive turns in one direction caused a single direction change whereas two curves separated by straight pieces contributed two direction changes. I'm happy to see it came down to something else other than actual track pieces, as nothing else in this game related to the track pieces used, instead depending on some other stat.

Thank you!