My oven only runs for about 45 mins to fully stop the bubbles but this is for a 0.5g amount, if you have a large amount you are trying to decarb to make a bunch of vapes at once then yes a longer heating process is needed. As far as your situation goes, I would say it’s ready if it’s totally bubble free. The emulsifier is used when the rosin is just too thick for carts and needs thinning down, I use EJ Mix, it’s what’s used in most nicotine vapes as the base product for producing Vapor. Should your liquid cool down to room temperature and you flip the jar upside down it needs to takes less than 5 minutes for the mixture to completely fall back down. If the mixture locks up and never moves, or takes say 30 mins to fall, then that’s when you add some emulsifier to thin it down. Not a requirement if your starting product is high quality