I think Fortydayweekend is looking for a way to do this automatically, but your suggestion would work.
So furniture without "Masterful Decoration" was being placed into a furniture stockpile that allowed only furniture of "Masterful Total Quality" (and masterful core as well I would presume).
Yep - all the furniture is masterful core so is also masterful total, no matter what level of decoration there is
I can only think of two things to try for your stockpile filters, both of which probably will not (and
should not) work:
-Disable all "Core" qualities to see if "Total Quality" can somehow override that.
(Likely result: stockpile accepts nothing)
-Make a test stockpile which will Take from the stockpile where the various decorated items are currently situated. Maybe that will allow the filters to work properly?
(Likely result: new stockpile takes items at
all decoration levels just like the old one)