Well, I did a couple more tests. Ambient air is 84 degrees and duct output 81 degrees. So a whopping 3 degrees.
I also dug out my refrigerant detector and I'm not really getting anything.
So Scott you may be right. As small as that capillary tube is it wouldn't take much to clog it. But what maybe a small piece of seal from inside the compressor?
And yes Keystone cheaped out and used a 13.5k. My old Springdale had a 15k and did a way better job with way less insulation. And the 15k is only $120 more
Leak or clog it all comes out the same. Not worth repairing.