Long story short; AC stopped cooling, replaced condenser, won’t cool on hotter days, radiator fan running on high speed.

Long story;

2015 Silverado 5.3L 2wd 75k mi. Purchased new. My AC stopped cooling and I put a shot of AC Pro in and it worked for a week or so. I took the truck to dealer for scheduled maintenance, oil change, transmission, driveline and cooling flush. Asked them to check AC. The service manager stooped down looked thru the grill and commented about the usual condenser weld cracking. They were unable to see any evidence of a leak so they recharged it with a shot of dye and told me to return when it stopped cooling again. I asked about the cost of the condenser replacement and they said they would check with parts and call me with a price.(still waiting on that call). About a week or so later it stopped cooling, I took a fluorescent light and saw dye leakage around the top weld of the condenser where the manager suspected. The next day I saw the manager at our local tractor supply and commented about his diagnosis. He offered me a better deal saying he could save me a couple hundred dollars to replace the condenser at his home where he and his son who is one of the wrenches at the dealership work on vehicles after hours. I took the truck to him on Monday evening and was supposed to pick it up the next day. He called later that evening saying there was a broken bracket and he’d get one the next day. The next day he texted and said there were no brackets in the area and he’d have one shipped in the next day. Texted me late the following evening saying the truck was done. I picked it up the following morning with no one at his home, it was a cool 50’s morning, the truck started up with the AC blowing full blast on Low temp. I let it run a while to insure it was cooling noticing a louder than normal fan humming from under the hood. Seemed to cool good so I shut it off and left. Didn’t try it again until a few days later when I’d pulled the truck out of the garage and it was setting in the sun most of the day heating up the interior pretty hot. I took off for town in it and turned the air on. It seemed to cool slightly but then was just blowing warm air with the radiator fan roaring on high like it was ready for lift off. I’d never noticed it making that much noise. I called the man and he said bring it back the next evening. The next evening I pulled out of my garage on a cool 50s day again and headed for his place. I turned the AC on to see what it was doing and it worked great about freezing me out on the way. I stopped short and called saying it was working now and I’d play with it a couple days and let him know. The next hot day I let it set out in the sun, started it up, turned on the AC, in just a few seconds the radiator fan took off on high speed but no cooling. I took it back to father/son garage, they checked the Freon level with a gauge set, hooked up a code reader to the OBD port under the dash and the 2 of them went back and forth for 20 minutes or so and then said it looked like a bad compressor. He quoted me $800, jotted down my serial number and said he’d call me the next morning with a price. That was Monday and still haven’t heard from him..
I’m not convinced that they’re sure it’s a compressor or now a computer/controller problem. My thoughts are that it worked fine with just a shot of Freon from me or the dealer and the radiator fan only running on high speed now that wasn’t an issue before is just making me uneasy about paying another $800. Or maybe I should go elsewhere. Any thoughts or advice would be appreciated.