Hopefully it was this thread prompted you to check your post 2014 specification chassis for cracks? That was the idea as it seems unlikely that there will be any recall action on this, desirable as that would be.
I notice you mentioned there were no cracks on your 2015 chassis at 45,000 miles a little over a year ago MOG42, how many miles have you done since you found the cracks? This may help with defining a period between checks. I know that I checked my car 5,000 miles ago before noticing this crack. My feeling is every 2000 miles at the moment.
I suspect that for every M3W owner who sees a warning on Talk Morgan, there are ten who never look at it. There must be a lot of blissfully ignorant M3W owners out there.