Rumble pit only has a few good maps to play on.
Haven
Adrift
Simplex
Supposedly majestic maps are in this playlist but I’ve never seen them.
The other maps I despise playing 8 person FFA
Dispatch
Shutout
Abandon
Give us more forge maps and I will be happy. Right now the selection is horrible.
It is a shame I don’t get to play the majestic maps because they are the best in the game. And as far as forge maps go the community forge playlist had better ones than what is in rumble pit right now.
Also 6 person FFA would be better, without instant respawn.
I’d honestly settle for a Retro map pack. People have made classic maps. Why not implement them?
I’d honestly throw my Halo 2 Slayer gametype up for 343 to test and tweak to work with classic maps.
You can create your own forge map an submit it to the community cartographers 
I agree with what you said. The biggest problem I have with any FFA Mode in this game is the instant spawns. It’s annoying when the last person you kill spawns ten feet away from you, and kills you with one shot because they just lowered your shields when you killed them last.
Instant respawns need out and lower player counts need in.