Alright the Program has been Updated you will find the recent Update in the Changelog.
The Storyboard is now able to keep up with very fast BPM's:
Hatsune Miku - Gekishou should work perfectly fine now.
Hypernite Industries - Speedcore 300: There has been a major imrpovement here, but it only works for 99%, there are still about 3 notes during the song, where the Timing windows overlap and you see a false "Good". I guess Arrow Streams in 300 BPM can still somehow trigger this under rare circumstances.
I'll try to improve it further in the future, plz try to bear with this for now, sry.
Well but the creators still need to reupload them, cause they might want to recreate the storyboard more than once, to get a "better possible result".