Yeah it can be a little overwhelming at first, but it's a good idea to get used to it and adapt it as your defaullt speed.
At higher difficulty levels there are songs, where 2 Notes are only minimal distances apart, and on lower speeds it can seem as if they should be pressed at the same time (due to the notes being squished together more)
You can see this in "Paper Plane" amongst others. Also in "The Story of Seattle II" (If you look closely you'll notice that MOST double notes need to be pressed at the same time but 2 or 3 times throughout the song they should be pressed at slightly different times)
Anyways

TLDR; 9x Speed is hard at first but it's smart to get used to it!

:D The design of the scenarios are super awesome. Though the one that looks like a drawing is quite hard to play, they did a great job :D
Aaand thank you! 9x speed is insanely fast, at some songs, my eyes can't follow

I always loved how the scenery changes on this design in certain songs, with the sky turning red and all. Nice Progress!

nice,you re a machine