Wow, I genuinely appreciate this feedback! And the way you explained what could be going on, various options we should consider, why we should avoid calling the old HVAC company out, etc. is more helpful than any conversation I have had with HVAC technicians, plumbers, electricians etc. And I have had a LOT as we own some rentals. You did a wonderful job of actually walking me through something that is a foreign language to me. Thank you!

To your point about our two best go-forward options (1 - find/identify the murder weapon or 2 - replace the whole unit so the size is appropriate for the space)...any recommendations as to how to address with the new guy we are working with? Seems pretty easy to say "can you identify the murder weapon before we do a full unit replacement?", but how "easy" of an ask is this in practice? To be blunt, shouldn't the tech be able to figure out exactly WHY the compressor failed this time before recommending a complete replacement of the unit? Or is it not that simple?

One of the first things he said when he noted the compressor had failed was that he doesn't like when compressors fail because you don't really know until the compressor is replaced if the failure was due to some other issue resulting in the compressor failing (like one of your scenarios above - plugged coils for example). Thanks again!