New Suggestion:
After countless frustrations from the imbalance of essence to flux a "fix" in my eyes would be this.
A Flux portal much like the current portal system it would drop flux instead of essence.
I see some issues that will arise in the comments from the peanut gallery so let's try and fix some before they come up.
1. I understand that flux can't drop every time other wise you could make 200+ flux a day. Having it drop every 2-3 rounds is fine as some people (B comes to mind) only needs one flux type.
2. "What about current portals?" I really don't think they are ever hit so I don't see that being a real issue
3. "Won't that make people just hit the portals instead of raids" well yes and no. On my justi I need like 200 indigo to finish my eregen set so I would hit that portal on that toon. I don't hit raids with it anyway, but toons that aren't close to maxing i.e. lvl6-8 enchants will still raid.