Not sure if it was on ASR or elsewhere, but I read some post saying that the heat generating devices were now out of the potted assembly. So, it shouldn't be any issue with reliability in PA5 II. I personally never turn mine off.
I don't see where the problem with potted devices is. All ICs, high power transistors, and regulators are just that anyway. Once the heat management is correct things work. There may be some Topping proprietary solutions there, but leaving unpotted some miniature SMT components won't make the module more serviceable. I can tell from experience that replacing components smaller than 0603 is not fun... If repair is required it will be direct module replacement. Nobody cares to troubleshoot and repair on component level circuits that cost a couple of bucks to replace.
I don't see where the problem with potted devices is. All ICs, high power transistors, and regulators are just that anyway. Once the heat management is correct things work. There may be some Topping proprietary solutions there, but leaving unpotted some miniature SMT components won't make the module more serviceable. I can tell from experience that replacing components smaller than 0603 is not fun... If repair is required it will be direct module replacement. Nobody cares to troubleshoot and repair on component level circuits that cost a couple of bucks to replace.