I find the references to file extension kinda confusing. Extensions mean a lot less in Linux cli, but I can tell youre just using them for examples. Maybe give more concrete examples instead.
We had one installed this past summer. Went with a top of the line Bryant and I don't have any regrets. This winter natural gas prices shot up and even on below freezing days, the heat pump just does its job at keeping the house a consistent temp.
It's already happening