FFA free for all mode
This MUST have been suggested already, but there should be a second game mode that's a free-for-all (FFA). I'm not sure how much development and time this would take to get underway, so I'm taking the magic wand approach and making as many wishes as I want.
Here is a list of features I'm proposing:
Game feel:
1. It's endless (or, matches last a very long time and you can join games in progress; new players are dropped in like they're respawning).
2. When a player leaves, their kill total and damage total are announced, almost as an accolade for participation.
3. No knocked-down mode.
4. Respawn points throughout map.
Arena:
5. The arena is one, two or three adjacent subzones of King's Canyon, and the rest of the map is locked off by the wall of death.
6. The arena's subzone(s) change on a rotation to keep the game mode fresh and attracting / dissuading players who do / don't like the Swamps area (for example).
Legends:
7. Legends' tactical and ultimate abilities are limited (longer cooldown timers).
8. A Legend is chosen for you, because 25 Gibraltars isn't a good idea (THROWIN SOME COVAH FOR MY BRUDAS).
9. You can petition for a change of Legend in an in-game menu; if the player with that Legend leaves, you'll have a chance to be switched to that Legend.
Weapons / Loot:
10. Loot is obtained via supply bins, of which there are plenty.
11. Once opened, supply bins run a randomized timer (say, between 3 and 8 minutes) before they close again (or, more realistically, respawn) and are replete with loot.
12. Spawn rate of some items would need to be altered (eg. no Ultimate Accelerants, more ammo).