So both my friend and I have revived other players from the DBNO stage or when you fully bleed out and haven’t had it pop. Healing aura has worked for some people I’ve played with but only from a certain radius. The only for sure method is to straight up revive them in the regular downed state. Being cod players the best strategy for this is to follow a player heading into the medium threat zone where they are more likely to down from a vehicle blowing up or for rushing in without pack a punching and being overwhelmed. Monkey bombs and stun grenades are your best friend to buy time. If you really want to cheese it I got this by having my friend join another squad and intentionally down. But for solo players just be close to another squad and be ready. God luck!