Again, that answer is beyond my field of expertise - I don't know if it's an R2R limitation, or whether it's a design decision by Denafrips.Right, but is this limitation inherent to r2r DACs or are there any that don't have it?
I also can't say if this is inherent to all R2R DACs as I only know Denafrips.
If this is of importance to you, I suggest you look at other manufactures and see what they offer. What I do when I want to know the particulars of a piece of gear is visit its site and download the owner's manual.
Good luck.