Considering that you can only refine 8,000 dilithium per day, then you can only refine 800 Omega Marks per day. That much can be refined in 4 minutes.
This way you have still the possibility to pack a little bonus on top. This could look like this:
50 Marks = 500 Dilithium
500 Marks = 5000 Dilithium x 1.01 = 5050 Dilithium (a Bonus of 1 %)
5000 Marks = 50000 Dilithium x 1.02 = 51000 Dilithium (a Bonus of 2 %).
This isn't overkill, but it would be a little bit for those who got lots of marks and could get a one of these bonus-packages. It could also increase your Reputation with Task Force Omega/New Romulus a little bit more then those 5 Points per 50 Marks.
Sorry that I didn't mention this in my last post.
If Star Trek Online was an Open-Source (GPL) Game, we would have a low-grind fork.