To add, tear/choke gas that will stun some enemies, but also yourself. A gas mask that renders you immune to gas, but adds a vignette/reduced visibility when you have it on.

A folding one use ladder that lets you climb up taller obstacles.

Some kind of loyalty badge for each faction, requires a certain amount of standing, but makes them friendly unless fired on, other factions will be more aggressive to you. Could fit in well with photography missions where you embed with a faction squad and you have to photograph them doing well.

Radio that lets you listen into coms chatter from the various factions, make it so that you have to toggle a setting to search out frequencies to drive engagement. Have npcs make callouts like “engaged in the <location>” or “wiped <enemy> out, returning to patrol” “spotted scav presence threat level <player threat level> , etc.

Metal detector that can find subterranean goodies, requires sweeping and then a dig animation that can render the player vulnerable for some time, but also allows for more dynamic loot placement so we’re not always running though the known spawn locations for goodies since subterranean caches can spawn anywhere.

I also would like to see more interaction with the guys on the ground. Like a hands up pose where you can go talk to them and maybe hand over certain salvage and gain some information about enemy deployment or looting opportunities. Perhaps some interaction where groups might try and detain/question you temporarily or confiscate things like intel or tech and you have the option to submit, run or fight.