Static sag doesn't really mean much aside from telling you if your spring rate is correct.
Get your rider sag right, then check your static sag. If static is roughly about right then you've got the right springs. If your static numbers are almost nothing, then you need a heavier spring, if they're too high then you need a softer spring.
For the most part on the road (unless you're super picky), static sag doesn't really have much baring unless you've got nothing at all. Concentrate on getting your rider sag correct first then if static is out, sort your springs out.
To a certain extent, you can compensate a little with Comp/Rebound if your numbers are off. Really depends how much money you want to spend to get it perfect.
Sounds like you've got the same problem I do. *** is too big and the shock/spring isn't up to the job. You could get a bigger spring and get the shock revalved/new shock, or go the cheap way and wind your preload all the way in and bump up your compression a little to help. 43mm is a bit high, but it's not extreme. Wind your preload collar all the way in and give the adjuster a half turn and see how it goes, if it's still terrible you may have to look at getting a heavier spring and getting the shock internals revalved.
Edit: If you plan to remove the spring yourself, be careful because the Zed's springs have a decent amount of preload on them with everything wound out. Get a nasty case of spring flying across the room. Def invest in a coil compressor or get a pro to do it for you.