Why not have a "Standby Missions" board where you can offer space on your ship to ports you're already committed to going to?
For example. I dock and collect a commodity (but either there isn't enough available to fill my ship, or I can't afford any more), maybe accept a couple of missions, plot my next couple of jumps accordingly and then choose to offer my remaining capacity on a "standby" basis effectively offering the unused capacity at a discount as my ship is going there anyway. So rather than cycle through the boards looking for missions that match my flight plans, I advertise my flight plans and see if anyone is interested.
For example. I dock and collect a commodity (but either there isn't enough available to fill my ship, or I can't afford any more), maybe accept a couple of missions, plot my next couple of jumps accordingly and then choose to offer my remaining capacity on a "standby" basis effectively offering the unused capacity at a discount as my ship is going there anyway. So rather than cycle through the boards looking for missions that match my flight plans, I advertise my flight plans and see if anyone is interested.