If you can’t find something custom to do this you might be able to fill the blank squares on your grid with empty buttons. You can define a theme to make their background and borders transparent. I have something like this (less complex than yours):
If you can’t find something custom to do this you might be able to fill the blank squares on your grid with empty buttons. You can define a theme to make their background and borders transparent. I have something like this (less complex than yours):
