Congrats and welcome to the glider world.
"the younger they are the easier they are" is a myth. Some joeys ( young ones ) are easy, some are hard. Some adults are easy, some are hard.
Age has the least to do with it in my opinion.
Sounds like your progressing pretty well and the gliders have settled in.
"Main question here is, how long to wait for them to get comfortable before starting to try to handle them outside the pouch and starting to try and take them out of the pouch by hand? "
I would recommend more tent time before handling them out in the open. In the tent they are contained so if they get away from you it's easier to round them up.
They don't have to come out of the pouch in the tent if they aren't ready, that is when you sit down with their pouch in your lap, roll it down a little and pet them and let them start getting used to your hands.
Gliders will usually fuss less if you roll the pouch down before reaching in, it's not as intimidating as a hand plunging into a deep pouch that will likely result in them biting you for invading their space. Rolling the pouch down also encourages them to come out onto you on their own since they are already more exposed anyway.
Please keep in mind, most gliders do not like to be held, they prefer to just be on your body or in your clothes rather than being confined by your hands. If you try to hold them especially when awake, they will likely do their best to squirm out of your hands biting if necessary to make your hands release them. UNTIL the gliders DO stay on your body, keep using the safety of the tent.
The easiest way to get a glider out of the pouch is pushing the bottom of the pouch up to the top or rolling the pouch down as far as you can so it looks like the glider is in a boat, rather than blindly reaching your hand in there pulling them out. Blindly pulling them out risks pulling their nails if they are clinging to the pouch especially if they haven't had their nails trimmed...
You can start doing this any time but work on it gradually, if the glider seems stressed out just take a step back and pause when your ready and the gliders are calmer start again.