Regarding the difference the new AHM7EC8B can bring to DSD1024 when paired with a direct DAC, here’s just one example.
DSD1024 with a very good modulator we are used to (IIRC, ASDM7ECv2 here):
When we switch to ASDM7EC8B:
We got about 10 dB improvement! In some other cases, the differences are bigger, and sometimes smaller.
Please note that this applies to DSD1024 and how the DAC is being driven by the modulator at these rates.