I use ConeColor inks, and generally print only using Photo Black. (I use Piezography and another printer for B&W work.)
I just decided to swap my PhotoBlack ink for your new Ultra version (having seen what an amazing different is had in Piezography, with the equivalent change.)
Fine… but now I need to clear the old photo ink from the line, and flush it to the new Ultra. I realize there is the old “initial fill” technique, but then this occurred to me: why not just do a switch to matte ink, then back to (the new ultra) photo ink. Wouldn’t that fill the PK line with the new ink and avoid the waste of an initial fill?