@idefix37 You are quite correct, however, my principal complaint is the near inaccessibility of the isoline button, if you will. It should be on the primary menu right up top where it can be recovered easily if wanted.
It is the only feature I know of that has the characteristic of frequently switching off when a change of background is selected. Those who do not use isolines wouldn't probably care if it were more prominent.
Not being a programmer I don't know how difficult it would be to affect a change. I think many would applaud this.
Thank you for your reply and clarification, James Flint