If I were manufacturing these amps and saw posts about mods making the amps sound so much better I would really be upset. Most consumers will not view this as a positive but as a negative.
If it is the case, where building is never a no cost objectivity, when making a profit is a consideration, perhaps it might be a driver in better future products? Which will cost more, which the modification also does.
We're still in the early days of the developing GaN amplifiers, I doubt we've seen even close to the pinnacle of SQ in sound available in the near future?? But then, who knows.