Here's my little dirty trick :
I download the Belleza demo body (well, I actually have the "real deal" - but I suspect that my alt just got the demo, typically her...), and get these four items.
With the "right-click-on-avatar"-hoverheight set so my bare flat feet touches the ground (around 0), I add the one corresponding with the height of the heels/shoe I wear, and saves that in the outfit. Voila, hoverheight basically corresponds with my shoes everytime I change outfits...
(I sometimes find that a hoverheight that is perfect in one sim, might be a bit off in another, but that is easily adjusted via the right-click or QuickPrefs. Seems like some floors or skyboxes at some altitudes migh have something to say?)