Stop potting. Based on my 35 years experience in electronics it is difficult to make it work properly without causing quality issues. It is also a nightmare for the factory processes.I don't see class d reliability as something special. Our issues mainly was due to potting. But there must be solutions, because power supply units have using it for ages without issues. It's just that we have to make the testing before production a couple of notch more hardcore.
And it brings you no benefits - only costs you reliability!
I think your stated reason was to stop your competitors reverse engineering your designs. It won't. One person (on his own) has managed to reverse engineer the PA5 module to enable people to repair their own amplifiers.
I won't add what I think about toppings CS that made that necessary.