Explorers need the Arx cap to roll-over.
I can see why it doesn't, because any exploits would become huge earners, but only getting 400 Arx after spending three months in the black earning peanuts is going to be a kick in the face. Even after December, and even if FCs get Cartographics (which they shouldn't IMO), not every explorer, probably not even most of them, will drag a carrier around with them.
Either the cap has to roll over, or the earnings from exploring must be balanced more toward the day-to-day work and not selling the data.
It should be easy enough to make the Arx happen day-to-day. Discovering new planets is not a cycleable activity. But if the Arx is going to remain concentrated in the data transaction, the cap must roll-over.