This may be a bit similar to a classic MOBA, but I think it would be absolutely amazing if Battleborn implemented this.
A 5v5, 3-lane board like a classic MOBA. Call it Battle Royale or something like that.
3 lanes and a jungle for melee characters or others of the sort. As for lanes, I say sentries in each lane leading to the base ship (one similar to the one we spawn out of). Putting mini-Varelsi as EXP camps or something, and adding turrets nearby the sentries like Incursion, except no Thumper turrets until the ship. I feel that the slow in a lane would be too OP.
As for how the sentries are, cover them with sniper nests or halls like Overgrowth or Echelon, so snipers can be in lanes alone or to have a place to retreat. Not sure how to prevent them from shooting down lanes, however.
The Thralls can be team objectives. Put Bonecrushers on the left and the Mercs on the right in a more open area for more competition between teams.
Don’t think buffs are needed, I think for the most part each character has their ups and downs and can handle themselves without one.
So that’s pretty much the rough idea of it, let me know what you guys think!