the Rep system doesn't seem like it will really take a lot to max.

More Star Trek related PVE content, random missions from Starfleet command, Exploration, actual PvP content, Fleet battles etc. There is tons of meaningful content that could be added instead another grind fest and money sinks.

the question was "How much?". So, how much do you think it needs.

Getting 8k/day is trivial, the cap becomes the problem when they add in 20k daily demand to an 8k cap.

B'Tran - 2880 (10-15mins)
IRP - 1440 (2 mins)
SFA - 480 (1 min)
Defera x 3 - 2400 (15-20 mins)
Thats 7200 in 40 mins?

Traelus is 3 mins.. Sh'mar is another 3 mins for 960 more.
Not to mention Doffing or STFs, turn in a contraband for 2000 is easy enough and can be done once daily without too much effort.

I already get around the refinement cap quite easily, and extending it per character would not ease the tedious nature of the grind.
Put simply, there NEEDS to be more and varied ways to get the dilithium.
Ie, they need to put dilithium rewards on most if not all story missions in the game as a start.

Getting 1440 dlithium for completing a featured episode for instance, is a lot more fun than grinding 3 dailies.
I would think it could mostly solve the one click quicky foundry exploit as well