Few months ago they came to do the maintenance and said the coil is dirty and need to put in 1.3K to clean it.  

The static pressure across the coils is probably killing the unit, if you dampen the registers it will only raise the static pressure.

My personal preference is old style coil tops, because the renters tend to ruin smooth tops with their cheap pots, but I'd do a cheap smooth top before gas. 

The unit worked but the coils were damaged by dogs.

After going into the attic they noticed the real problem was coming from the coil in the AC unit but had already spread...

Plus, this is a great tenant and I want to keep them happy.Some context:My property manager does inspections twice a year and provides air filters.The HVAC system is from 2018 (central air/heat pump).I’m thinking maybe one visit from a handyman to flush the drain and clean the coils, and one visit from a professional HVAC company for a full checkup.Curious what others would do in this situation.

All of the metal for the metal roof, is imported as coils for the roof and flat metal for the beams/rafters and purloins. 

I have a HVAC installer coming to give me an estimate for a complete install, Condenser, Furnace, A-coil, ducting, fuse box.

-------This week, we’re talkin’ more shenanigans with our government employment data, a spotlight on construction workers, and the coiled spring that is the housing market.Let’s get into it.

Yup, maybe if folks just actually changed filters, cleaned coils, kept air handler clean & didn't block of registers equipment would last longer