Not always true, could have pressure switches holding it out or other safeties. I can’t stand Freon it’s refrigerant. I would’ve asked where the leak was and also to get a copy of the work ticket
Natural gas is lighter than air so it rises, propane is heavier than air so sinks and settles, makes sense if this was a propane leak as mentioned before
I look at goodmans as the psa of hvac world, I’ve been impressed with runtru which is basically a plain Jane trane made by trane. Lennox is decent but sometimes parts take a minute to get. Bryant is a generic carrier
If money wasn’t too much of an option I’d go trane or runtru and up to 16...