Hello,
In my opinion the UI needs a refresh, it takes too much space on the screen when taking notes, we should have the option to hides things we don't use, thus clearing the menu bar for things we actually need, for example If I use a pen and marker only, I do not need to see the magnifier, shapes, text,laser icons, and also we need more than 3 pen\marker sizes & colors. to up the productivity for people who have to take fast notes (engineering), and want to save time with 1 quick click do it rather than do multiple screen taps that take 5 seconds total every time because of animations.
And also have the option to have the menu bar on the sides, so you can use the second hand to quickly change modes without having to lift the writing hand.
Also the marker should go behind the text on dark mode theme and we need an auto convert light\dark mode button like what apple has in the native notes. apps.
And last one thing is a streamline to make the notes more round for us shaking people :P
I wrote many stuff here, kinda in a rush because of an exam, but hopefully it will give some ideas to push to make the app better =]