I've got test cooling data from 5 hours of running this morning, starting at 78F for air temperature, 77F for floor.
Bottom line: Slab temperature down 5F, about the 1F per hour, as I was expecting. Slab a foot from the manifold down 10F. Air temp was only down 2.4F, but I expect that to continue to drop for the next hours.
No sweating at the manifold, BTUs averaging 10,860.
BTU's started at 12K, ending at 9.9K,
Current started at 3.9A and ended at 4.5A, 230V.
COP started at 3.9, ended at 2.8. (65F to 83F)
Outdoor air temp start at 65F, ending at 83F, fan inlet started 65, ended 85F. Liquid line temperature ended at 105F, a 20F approach, which is very bad, the condenser and/or fan needs work. This is the first time I've done a run with the case on, which seems to be restricting airflow. Fans and fins work about 23% less at 5600 feet.
My minimalist floor cooling approach is working somewhat but I have to wait a few more hours to see if I need more BTUs.
I forgot to add 1.5 degrees to the digital temperature on my wall to calibrate it with the other analog thermometers, and got over excited about performance. It's come down only slightly since I stopped the active cooling.
Edit:
Allowing for the 3 degrees F of gain I would normally get on a breezy 88F day, I did get about 4.5 degrees of benefit from 5 hours of cooling. So just barely meeting my needs.