I spoke with the folks at Nuccios Nursery in SoCal who specialize in Satsuki and Camellias. They recommend a minimum of 4 months to separate cuttings there, so 12 months would be safe in most all climates.
Also mentioned their experience is that Satsuki cuttings do the same with or without rooting hormone.
Cheers
DSD sends
He did cuttings not air layers. Cuttings should strike in about a month if he used current season flush that harden off. Based on his initial post which was March I would assume that was last year's growth. Depending how woody the stem was if could be 1-6 months to strike roots....all depends on the environment the cuttings were placed in and how woody the cutting was.
I guess I'm asking should I check them for roots after another month then repot. Or should I wait for several months or a year? I just don't want them to grow together.
To check if they rooted, you can lightly pull several around the pot if they resist being pulled out then they have rooted. As far as keeping them together or separating the cuttings.....that's personal preference. I like to separate a bit after they have rooted into separate pots, because if you leave them together their roots will become a tangled mess. During the pot up i spread the roots out evenly. Also if you leave them together you risk loosing multiple cuttings should one get diseased as they share the same pot and are in close proximity to each other.
1 pot = less space needed and multiple pots = more space needed............something to consider.
Here's some of my azaleas potted up to give you an idea.