1. Gustard's English wording is wrong. It shouldn't have said R2R when referring to DSD. It often happens that manufacturers have someone who isn't completely technically literate write their English materials.I also know that @Currawong was wrong on the second issue. Apparently a place he had identified as DSD ladder on the main board serve a different purpose and I have an idea what it could be... Gustard also initially wrote that there were not using dedicated DSD ladder, but R2R ladder. My opinion on that is as follows, listen carefully: there is a multibit DSD ladder on the DAC board, but it didn't work well, they perhaps resorted to 1-bit solution as a backup, hence all this confusion.
2. By default, the R26 is set to re-sample DSD to PCM and use the R2R ladder. You have to turn this off in the menu.
Why would a manufacturer put a DSD ladder in their DAC? Because... wait for it... it's for decoding DSD!