I just did some number crunching and if I hit the refining cap on both my Klingon and Federation characters I could get a pretty decent amount of zen racked up in a week with the current exchange prices.
Not that I like being a soggy sock in the pantry, but your comment raises the question of how are you going to hit the refining cap on all your characters?
. From my perspective, its only feasible if you already have heaploads of dil on every character, or are playing STFs non-stop for the entire day.
Well, with the latest patch, STFs on average are now giving more Dilithium then they did before (if you convert the BNPs and Omega marks to Dil as well.)
Elite STF now gives:
960 Dilithium (base)
Between 1-11 BNPs per run (5 BNPs = 500 Dil with a 15 second Omega Upgrade Project)
60 Omega marks (75 if you get the optional - 50 OM = 500 Dil with a 15 second Omega Upgrade Project)
So, if you do the 4 available space STFs on Elite in an hour or so:
960 X 4 = 3840
75 X 4 = 300 and at 500 Dil per 50 = 3000
and lets say in those 4 runs you get 5 BNPs = 500
So right there on a good STF 'round robin that's : 7340
(on a really bad day where you miss the poptional on every un,you need to do one more STF for a total of 5 to get 300 Omega marks - so add another 960 to the above and say you still only got 1 BNP per run, that's: 8300 Dilithium.)
And that doesn't include Dilithium from the two remaining quick click 480 Dil dailies that remain (the SFA 1 click lore mission, and the 6 click "Rescure Deferi Captives from the Breen" space mission.) Or another quick 480 Dil from the SB24 Fleet Action.
Also the Reputation missions for gaining Rep also reward 340 Dil for the 2000 rep gain; and 140 Dil for the 800 Rep gain.
So, yeah, with the latest changes, it's not hard to hit the 8000 dil cap in an hour to 90 minutes per character, Not too different from the Pre-S7 days.