After doing my own googling and spending lots of time in raids as a scav, I'd like to clear up some misconception surrounding scavs and time requirements in raid.
Recently I saw some comments on this sub stating that some people spawn in as a scav and then hide in a bush for awhile in order to secure the loot in their bag without losing its found in raid status. This isn't necessary because as long as the raid has been active for 10 minutes, you will receive a survived status. You do not have to be present in the raid for those 10 minutes.
If you'd like proof,
If you find yourself spawning in with some nice stims or a labs card, rest assured that as long as the raid has been active for 10 minutes, it doesn't matter how long YOU have been in the raid before you can extract.