"Is this a ligature or is it a homoglyph attack" is certainly a waste of cycles that nobody should have to endure. (why am I thinking of Scala all of a sudden, Scala has done nothing wrong!)

Perhaps if some radical homoglyph defenses get established they could also take this sting out of ligatures? (how about highlighting everything that cannot be typed with your current keyboard layout, or with the layouts in whatever quick access scheme you might have?)