It might be late for a suggestion but the line number on the left used to be shown on an information row either on top or at the bottom (just like your menus), it used to say Row: XXXXXX this helped keep the line number outside of the main editing screen, also some other information was shown there for example caps lock/num lock state or brief messages like Compiling.. , linking, etc... Just my 2 cents

Maybe someone is already doing this... https://www.breadbox64.com/blog/the-mechboard64/2/

Adding support for these type of menu is very thoughtful , I used all the Borland products and loved their menus, it also suits well the interfaces on computers in the early 90s! Great work!

If you build it, they will come... :)