The weekly Gambit Prime collector bounty takes unreasonably long. It gives you 10% progress if you bank 3 x 15 motes (i.e. send 3 big blockers). In my opinion that is quite a good score already. That means 10 effin Gambit Prime matches to get this done. Other weekly bounties are much simpler and faster to do. Banked motes need to count more towards the mote collection part of that bounty.