I'm also not a bit concerned about the "friend zone" issue. My wife is my best friend. Our friendship is one of the things that brought us through our situation over a decade ago. OM's usually become friends first before up'ing the ante, sharing feelings and escalating the relationship. You are supposed to be friends with your wife. It's not like you are going to sit there being her best friend during any divorce process let alone AFTER the divorce. If she divorces you.. the "friend zone" is unhealthy FOR YOU. There's a lot of water that has to pass under the bridge before you get there. If she keeps up with this "having second thoughts" and "I love you" words while her actions continue down this divorce path (and/or you confirm a continuing relationship with OM) then that would be her toying with your friendship and perhaps a reason to back out of the "friend zone" at that time.
I'm just not a fan of sending constantly mixed messages. I care versus I'm happy without you. Either you are devastated OR you couldn't care less. Which one is real?
I think Defacto is doing a good job of riding the fence. This obviously isn't an exact science.
The internet is 90% complaining and entitlement and I hate it because I deserve better!