J.R can comment his perspective on this. Here is mine:

We have a bit of a mixup here. On the one hand, I do believe that the "High bar for usability" goal has not been met, and doubt it will be met this month.
On the other hand, we moved to paying out monthly bounties in February, and .

I hope it is clear that the DEx bounties paid in Feb, and the March monthly bounty, count towards the 300 BTC bounty (out of which 150 BTC has been previously paid).
So after March I don't think that a lot of money will remain in the original 300 BTC money pool (J.R needs to reply with some numbers).
I expect the bulk of the money remaining from the DEx to be divided in March's monthly payout.

Perhaps if there is only a tiny amount left after that, we will decide to increase March's payout and pay out the full remainder of the 300 BTC bounty this month, in order to avoid the accounting/judging headache. We will wait for J.R's number regarding February's payout (due any day now), and see what makes sense.