Hi @ron1264 ,
I'm not an expertise in Class D amplifiers.
But all of them digital and PWM are very different from SET.
For example, most of SET fans use high sensitive speakers like: horns or full range drivers. And they like these speakers not just because they don't need huge power amplifier - but because dynamics, texture, transparency advantage over mainstream low sensitive speakers.
I can't imagine any benefits from class D for high sensitivity speaker.
About analogue chips for audio. Any small production parts "for audio" will cost crazy expensive. Look, for example , at prices for AN Kaisei electrolytic capacitors precising vs regular electrolytic capacitors.