Well... it's still going... my MTB 'Cricket Song' just opened the first flower on the fifth (and probably last) stalk of its second flush.
As I'd mentioned before, the clump couldn't be more than a foot across and had a main flush that began in late April or early May. I posted a picture May 4 or 5 that already had quite a few blooms open. This main flush lasted a few weeks and then things were quiet for a week or two.
The second flush has been 5 extra stalks - the first flower on these opened June 6.
Hopefully this won't have used up the Fall rebloom stalks.