As a musician I would love so much to see a tool in Goodnotes which would allow to draw perfect parallel lines for music staves in any length. The optimum would be to be able to select the number of lines drawn, from only one when needed for percussion/pure rhythm notation to five for the regular system and even up to six lines (for guitar tablature). The famous music app ForScore has this feature in pro version which works great, but the general functionality of drawing and colouring in this app is so poor, I feel GoodNotes is light years ahead. So for the creation of sheets GoodNotes is simply the best and for me it would be perfect to have the drawing tool for staves. A second suggestion and wish is to be able to lock the size of importing templates so for instance all guitar chord diagrams could be easily adjusted to the very same size/format.