It sounds like great progress! And I'm so glad to hear it, I missed this post yesterday and just sat down to really catch up on new news, other than quick pops here and there.
It is amazing and amusing how the glider's colony dynamics are and change accordingly.
Are you planning to wait till you have Fionn neutered than to try introductions again? I was just wondering, because you mentioned it looks like it will be coming up soon.
And I agree about the clicky noises from Luna being good sign. She wouldn't be making any positive sounds if she were annoyed by his nearness.
And yes the scent mingling is vital, even if it's getting obscenely long between washings. You can try using double blankies though, so you can give the pouches a little washing or at least a good rinse out in between. Than alternate the blankies and pouches for washing. Also, are you sharing "out of cage" toys between the two of them? If not, it would be a good thing to try doing as well.