I've noted several times here that the "hover height" adjustment feature that used to be available in Firestorm and some other third party viewers became unworkable when Linden Lab introduced the new Server Side Appearance baking.
LL gave us a clunky workaround with the Hover adjustment in the Body sliders of the Appearance menu, but this had serious drawbacks. It didn't work with No Modify shapes, and the adjustment increments were very coarse.
But now LL has incorporated a fine hover height adjustment into the latest Release Candidate viewer! For more on this, with pictures even, see the post over on Inara Pey's blog or the official Linden Lab announcement at https://community.secondlife.com/t5/Featured-News/Now-Available-Hover-Height-Improvements/ba-p/2916962