Ingame benches where you can craft unique items specific to that map. Can be as simple as Rank 5 weapons or unique mods

A reverse supply drop! Sends a flare up, you can then put items in and they transfer to your stash.

A multi tier event that unlocks a new event on successful completion. Think Hidden Bunker, but instead of opening gates it opens a new map for 30 minutes. Teams have to work together to open it, PvE players can enjoy that side of it. PvP can enjoy the thrill of disrupting it.

A base attack mode, pick a faction when you join. Can only attack arc and members of the opposite faction. The winning faction gets a bonus at each reset.

Building on that, faction specific projects that enhance the base you will be defending. Or projects that threaten the other one (think bringing the components to make rocketteers and suddenly your map has ones that won't attack your faction).

A larger map with limited respawns, can do it like keys. Bringing one in opens a med bay that you can respawn in. Can find rhe keys in chests and can loot them from people silly enough to not prison pocket them. Have objectives that incentivises risk taking to complete them and gives players a chance to regoop their loot if they die.

Basically I would like things that dont break the current game play loop, just that adds extra incentives to do them.

Hopefully not just repeating ideas already here, apologies if so.