I do have the center and the 'wake' tabs on my epic - and to be honest - I still haven't figured out what good they do beyond that I turn the boat into a submarine when it's fully loaded and I extend all tabs fully down
I was hoping that I would give me additional tip for surf setup (like left tank full - right tab fully extended) but it doesn't. If I try to clean up the wake it gets rather finicky and the first thing the boat is usually doing is going the other way (like I'm in a left turn surfing and extend the right tab and next is that boat is veering to the right despite me still having the rudder going left).
Now that may all be b/c of boat design - so don't take my word that the same will happen to you if you try it. In regards of the FAE: Yes that will extend past the trim tab - have it on my epic but you may want to tell Larry if you don't have a stock setup - so he will ask you to fill out the measurement form to ensure that it fits.