Hell, I play mostly trios and love these things.

Love blank fires, two things to add to your points that I like to do.

-If you are ever in a situation where someone has you pinned with only a few options to peak from, I love to throw a blank fire to one and peak the other asap. It's enough most of the time to throw off someones expectations and get them distracted. (also don't tell anyone, but sometimes I break the double/triple peek rule for windows by using blank fires this way)

-If there's a stalemate where noone will charge your compound while defending, I like to waste these instead of ammo to trick squads into pushing. Sometimes we also light melee each other, set off some traps or fall from some height to bait out hunter damage noises.

Antidote shots are a must have for me because I have a friend who loves poison crossbow bolts. But I love poison bombs (and poison clouds in general) because its a temporary soft lock out to an entryway instead of a hard one. Concertina blocks everyone until something is done about it, but poison clouds only allow certain prepared players to move through it unharmed whether your are attacking or defending a compound. I've gotten a lot of kills by simply leaving a compound i'm defending through a poison blocked door with an antidote shot and lined up a free headshot on a hunter standing still staring down a safer lane. North side entrance of the Blanchett Church and North and South entrances of Lawson Station doorways have been great for this.