Hi Kelly and welcome back. It's nice to take a break every now and then, right?
As for your timeline for your b/f to resume therapy, I don't know that you should really have one if things are progressing or at least stable. When he's ready to go back, he will. I remember a post from David (MemoryVault) a while back in which he talks about times when he wasn't in therapy and not doing much of anything proactive to promote his healing. He thought about this past time and realized that while he may not have been "doing" anything, he was still healing. He was working on himself in his real life by holding his job, taking care of himself, taking care of his place, learning how to deal with people, etc., etc., all very, very important stuff. He was working on his healing, just not in a way that most people would notice. I can't remember the name of the post, but maybe someone else will.
I doubt very seriously that 4 months of therapy have cured all the ills that csa causes, but your b/f may have gotten all that he needs out of that 4 months to last him for a little while. He may be digesting things he learned, adjusting to it and putting a few things into practice to see if they work.
My point is, if your b/f is feeling good and treating himself and you well, but just isn't ready to go back to therapy, that's not necessarily a bad thing. Can you talk to him about it and simply ask what he thinks he'd like to do?
If you fall down 10 times, Stand up 11.