Here's my theory.
- Flurry does
not stack on itself.
-
However, it does work independently on each hand, just like crusader, so you can have 6 total charges. Like crusader, that isn't visible in the buff icon.
- If an attack procs flurry, it doesn't consume a charge.
Row numbers in my spreadsheet match yours.
Thoughts? It does seem to fit your results.