wet insulation provides zero insulation.
My thinking is that the attic temps are high
insulation is minimal inside unit. condensation forms.
over time the condensation wets the insulation
as it is saturated and can not absorb more water
it drips.
we have this in my area also.
dry existing insulation as much as possible.
sealing the pipe, electrical and mechanical & plenum connections will stop hot air from entering the unit.
(as hot air meets cold temps dewpoint is reached and condnesation forms)
insulate unit with R-8 ductwrap on all sides
even bottom.
the air sealing will stop attic air entry
the added insulation will lessen temp difference on
metal.

best of luck.

I want to thank everyone for their help and very good input. My awesome HVAC team put in an EZ Trap hooked up to kill the unit if the trap fails and a regular trap on the secondary. Since then the pan was dry but now a month after the install, there is a little water in the pan. I think it's from condensation with water dripping off the unit where the blower pumps the air into the main ducts. When I feel under there, I can feel droplets of water and these seem to be slowly dripping into the pan. The pan only has a 2 mm of water in it. This is the maximum amount of water in the pan and always in the same place and I've been checking every 4 hours.Is this a small amount of condensation dripping a big deal or something to be expected with an attic HVAC install? Is there anything I can do about it? Is there anything wrong with my unit? Please see photos below.

Here is a link that might be useful: Small Amount of Water in Pan after traps installed

If the backup pan has water it means the main pain is NOT draining correctly.

Use a shop vac to suck the drain clean.

so they drain the pan, but did not figure out what is causing enough condensation to fill it?

the pan filling up is a symptom
the problem is the excessive condnesation.

you've got a handle on where the water is dripping from.
if you open the unit the insulation inside the unit is wet
and exits where you described.
mastic seal unit connections and plenum connections
and externally insulate the unit.

its a good thing that your hvac company got the pan to
drain properly, but problem solving rather than part changing would solve the cause of condnesation.

Make sure you have a positive slope along the entire drain line. Years ago when I had a new unit installed in the attic they installed a new P trap where there was none before (now required.) At the right angle turn for the line below the main floor (basement ceiling) there was a section of the line that was negative slope which transitioned into positve. This negative section was acting as a P trap all along. Now, with the new P trap installed in the attic I had in effect TWO p traps causing an airlock in the line thus causing overflow into the pan. One P trap will prevent back suction. TWO P traps will prevent proper drainage of condensation