CIO seems as though it will be INCREDIBLY difficult if you're in the same room. It will also be very hard on you.
So you're bringing him in the bed at night.....If it's working, what's the harm in helping him (and two working parents) sleep at night? It's not going to hurt any of you to have him come into the bed occasionally. And since he's able to go to sleep on his own, I think this is just indicating that he still needs you at night. There's nothing wrong with a baby wanting mama at night.
You say that there has been a lot of fluctuation in his care since you went back to work. It makes total sense to me that he would need to regain some normalcy for himself and reach out to you at night.
Congrats on being able to stay at home again soon! Perhaps once you are staying home again, he'll feel ok to sleep more at night.
My children didn't use pacifiers (besides me, LOL!) and I don't use CIO, but I would think - just me guessing - that anything that aids in self-soothing would be acceptable. Still, I don't think this would be a great method for you in the middle of the night with all of you being in the same room.
I promise you that taking your baby in the bed at night is not going to ruin him! He'll stop doing it when he stops needing it. He obviously needs it right now, though, and I personalyl would do what he needs.