UV does have it's applications.

However, It is expensive for the normal, low maintenance homeowner.
UV does have a 1/2 life, something the manufactures have not
advertised so well in the residential market. A fact that some
contractors themselves have not embraced, I wish I had taken pictures
of their faces when I had them actually read the literature.

Evaporator Coil (specifically pan) properly installed should not have
standing water so this is not my concern with mold. In fact, it
should not be taken into my consideration for recommending a UV
system. (But what can I say, I push routine maintenance too.)
However, I do live in a rain forest where RH is extremely high. It is
the health of the occupants that determine if I recommend an UV system
and I do take the time to explain 1/2 lifes, etc....

I find that a properly installed system with a healthy family do not
require the addition of UV, there are other, cost effective systems
that will keep IAQ well within acceptable limits for a majority of
households.

But here is a question for you techies: Ever try to tar your
environmental test equipment outside within "environmental norms" to
find the house way below (meaning lacking even the slightest trace of
natural pollutants such as asbestos or CO found in the area?--and no
UV installed?)