I noticed that the width of line number margin is always equal to 3 characters initially no matter how many lines the loaded file has. Which is fine if there are fewer than 999 lines, but if there are more and you scroll past line 999, the width of the line number margin increases (to accommodate one more number) and the whole text shifts sligthly to the right as a result. The opposite happens if you scroll back up to the top of the file - the line number margin becomes 3 characters wide again and the text/code you are looking at shifts left again, which is slightly distracting.
Also, when you have fewer than 99 lines of code, the line number margin is 1 character too wide. I think it would be nice if the editor automatically adjusted the width of line number margin when the file is loaded depending on how many lines the file has. If <99 lines then make it 2 characters wide, if <999 lines - then 3 chars wide and so on. This would eliminate dynamic adjustment during scrolling and jerking the text to the right or left.