Nope, your 2 paragraphs work nicely.

I can see your point about adjustability, although the taper of the Holdfast strap grips my foot pretty evenly. It's definitely not universal, so what works for some won't work for others. I do love the double straps on my road bike for the same reasons you mentioned.

However, I've never "slipped out" of my Holdfast straps, so that hasn't been an issue for me.