I like your comment on "no false positives". If you see it it REALLY is there. I also agree that a negative finding isn't always indicative of nothing there.
However, mirror choices are a bit like saddle choices, one size doesn't fit all. I tried all of the available helmet and eyeglass mounted mirrors several times and never got used to them.
After trying every alternative I could think of, I settled on the Third Eye bar end mirror. It's very stable and, at 3" in diameter and slightly convex, it gives a wide view. And, yes, objects in the mirror are larger (and closer) then they appear but you learn to compensate for that quite quickly. This mirror has the further advantage of always being in the same place. so you can quickly glance at it for an update.
I install them in the left end of my drop bars for riding here or in Europe and move them to the right side when riding in the UK or Japan. Their one disadvantage is that they precludes the use of bar-end shifters. Not a problem for me.