For myself after reading all these, no matter how well topping measures and sounds, I would avoid their high power designs for amps or such. Dac and headphone amp is very likely fine but higher power like speaker amp in a confined box is a no to me since they don’t seems to dare taking the cost to fix their reputation or reliability issue.My PA5 works and sounds Great! Listened to it for about 10 hours today so far in 77 - 78 deg F. I am sorry you had such a bad customer service experience, but I recommend you consider fixing up your PA5 and giving it another go. There are other great low power Class D amps for sure, but not sure if any meet the specs or sound as great as a working PA5. I do have a Fosi V3 on the way, and a 2nd SMSL A300 for bridgeable mono, but I can only hope these sound nearly as good as the PA5.
Other solutions might likely get u worse sound, but barely perceivable, and no degradation in sq more than a broken amp