I'm sure pcm1792 has a dedicated converter with 67 taps from 1bitDSM to an analog signal. I have the document about the principle of their 1bitDSM converter written in Japanese(I don't know English version exists or not). From the datasheet, AK4499 also has a shortcut to the final stage. Theoretically speaking, bypassing an internal modulator means non-multibit: 1bitDSM.
Marcel was very kind in modifying his original PCB to accept a 'raw' DSD data stream. I really ought to kick myself to make some more progress with the project but I'm trying to clear a couple of other projects off my todo list first as I've been spreading my efforts to thinly.