David,
You are to be congratulated heartily for your zeal in experimenting and
thanked for sharing the results with us.  Having had initial indications of
promising lines of enquiry from this year's experiments and presuming that
you will take the commercial risks involved in continuing your experiments
which must involve some time/money and potential loss of crop, may I make
some suggestions for next year's experiments?
Use controls where possible.  Separate out results from different treatments
so you can tell whether it was the essential oil or the FGMO which was the
decisive factor.  Recent posts suggest that FGMO is not as good as was once
thought but unfortunately this cannot be confirmed or denied from your
results.  Use your own colonies for comparison: your neighbours probably will
not have been smoked and disturbed as often as yours and this may have a
bearing on the mite fall.
The fashion in alternative treatments seems to be tending towards essential
oils in one form or another.  If you have sufficient resources and interest
it might be valuable to compare one with another.  As a queen breeder with a
commercial interest in drones you might be the ideal person to follow up  and
possibly improve upon Jan Templeman's  helpful suggestions involving
manipulations of drone comb.
Regards,
Chris Slade