When a piano MIDI file is imported into noteflight, the treble and bass clefs are squished into one, and if the bass is a different rhythm to the treble, then all notes are shortened to fit in one voice. This is really annoying and the clefs take forever to separate. The coding for this may be hard but I would appreciate if it was fixed.
You’ll be excited to know that Noteflight now offers the option to open your score in Soundtrap, the amazing online DAW! That gives you immediate access to a lot of the things requested here.
Just go to Export and choose “Open in Soundtrap” (requires a Soundtrap account).