In 2012 I wrote an article about Full Digital Amps. I just updated it a little. That's one part of the news.
During those days I was trying and tweaking several of these FDAs. I really liked the technology and the idea behind it. And they sounded extremely clean and dynamic already back then. IMO cleaner and more dynamic then most DAC-amp combos I had listened to. In the article I describe what I didn't like and why I left that idea alone. Just to mention it: It was mainly due to the mediocre digital pre-stages of these amps. These amps also need top notch USB receivers, filters, clocks, DSP/SRC, power supplies, regulation, layouts, isolation etc. During those days that's IMO been a major weak spot.
I still kept watching for developments. Not much was happening over the years.