Reading your story, I can't help wondering if your W chose on purpose an unavailable man for her EA? That it reflects her hesitation in stepping out of the M?
I hope you continue to get good results - it sounds like she is responding really, really well to what you're doing. Your story generally sounds much more hopeful than many others I read here. I'll keep my fingers crossed for continued success and that she comes to her senses.
Please be very alert to what kind of counselor she ends up with. Not all are good and quite a few have the attitude of 'do what you feel like to make yourself happy (even if it means leaving your family in ashes)'.
M 16 yrs, WH62, P54 3 adult blended kids EA 11/13, BD1 6/14 PA fall 14, BD2 2/15 Piecing 2015, BD3 12/15 Separated 4/16 WH moved OW in 5/16 Divorced 6/15/17