> I have managed my hives with two queens for 20 years.  I use all western
> supers so that they are easier to lift.  With a good queen in the bottom
> hive it may be 10 or 11 westerns high.  I use an excluder over the bottom
> brood nest, then the supers, with the top queen over a ventilated
> (screened) bottom board device.
 
This sounds like a variation that I have not before seen: apparently the
 bees in the upper unit do not have have access to the lower supers
without exiting the hive and re-entering below. I'm curious how many boxes
are used for the lower brood chamber and also how many for the top unit.
 
Moreover, I gather your neighbour to whom you refer further down does not
have any communication within the hive due to the plwood bottom piece.  I
am not clear how this is then a two queen hive rather than one hive
sitting on top of another hive.
 
I know of Charles Mraz's methods and have practised them, but thinkI must
be missing something here in reading your description.
 
Allen