What's "super long"? Three minutes? Ten minutes?
It seems simpler to just provide a specific maximum length?
I assume you want race maps, as opposed to more trial/platform feel?
Fullspeed...yes/no? Thread-the-needle maps? High-transition maps? Should CPs be respawn friendly? Multiple laps?
I suggest that you post links to the previous two map packs, so builders can get some idea of the sort of map that was approved for competition in the past.