Wow! No love for "The 7ender Float", I see!
While getting a 7ender bridge to work correctly and not one's strings out of tune is difficult, I enjoy the challenge and because I'm such a contrarian by nature, I enjoy using them with a float (just like Jimi did).
I can offer a little "trick" which, anecdotal, seems to work reasonably well:
When you're using your tremolo arm, if you can, make the very last move a quick (very quick) half of a dive bomb. How far down you go isn't as important as how quickly you snap it down and allow it to snap itself back up.
That seems to help the tuning issue, a little bit.