I'm often surprised at how good some companies are in responding to technical questions.
I’m in UK and NAD is in Canada, but if I ask a question via their BluOS control app > Help > Online Support, I get an immediate acknowledgement and a proper reply within a couple of days by email that I can reply to if necessary – I do hate “No Reply” emails! Once or twice with particular problems, I've received an international phone call from a senior advisor and in one instance, they have taken control of my PC to get a particular qlitch fixed. No complaints.
With Avantgarde Acoustics in Germany, I’ve also received excellent service, after raising a question via their UK distributor that was beyond their knowledge. Again, within a couple of days, I received photos and detailed instructions on how I could cure a couple of problem that had developed with my 17 year old Unos. I followed these (after buying a couple of small resistors) and fixed both the start-up bass amp thump and the "scratching" noise that I was hearing on one bass driver on some tracks.
Best to deal with companies that value their reputation as both NAD and AG seem to do.
Peter