Earlier quoted context omitted.
I don't think that would solve the problem. "The word "not" is faintly showing, what does that mean?" It it was trivial to show a single clear indicator word, they could just show a clear indicator line, then there'd be no ambiguity. It's not the second line that confuses people, it's figuring out if that line is really visible enough.
But when the line is faint you get false negative from the machine.
It the digital reader can't detect the line, that should be a limitation of the test strip, not the automation. And it should do better than an untrained human.