I think there are a few caveats with MAQS.
But it is a splendid option for *in-season* treatment.
Don't use it at "Apiguard Time", after removing the crop.
If it should give a problem, its harder to fix so late in the year, and upsets the winter prep.
That is also the time when wasps & robbing can be a problem, and MAQS wants ventilation - fully open entrances are mentioned in the instructions.
Instead,
use it earlier (when situations are more easily fixable) and
extend your season - you can leave the supers on for about a month longer! This has to be of particular interest to those with a late crop from the Heather.
I'm not fully convinced that the instructions are right for the UK. They are aimed at wooden Langstroth boxes with solid floors and holes in the coverboard.
A single brood (small) poly (warm) national with a no-hole coverboard and OMF (very different ventilation) is a rather different situation.
One strip may be enough, especially for warm polys.
The coverboard hole might just be very important on this occasion (its something I think is inappropriate for most of the year), to encourage a bit of through ventilation. With an OMF, I think its more important than the instructions note about fully-opening the entrance.
If there is a problem with too-strong vapour, its most likely to be in the first day or two. I'm not convinced that the vapour concentration is steady over time (but it may not be meant to be). Hence getting enough ventilation is most important right at the start of treatment.
DON'T sniff around to 'see if it is working' ...
