setting for printing in Fresco

Ah, ok. I see 🙂
What I meant in that specific line you quoted was that if it was impossible to print anything properly *without* CMYK, then digital photography would be unprintable. And clearly it is not.
I guess a lot of people mix up color models, color spaces and color gamuts as if they were the same thing and decide that if some color can't be printed is because of the color model and not the color latitude of the medium.
The reality is quite simple: There are many RGB shades that can't be printed basically because CMY inks are imperfect. Specifically if producing perfect pure and saturated cyan and magenta inks was easy and cheap, we wouldn't be having this conversation and we all would be sending RGB to print shops happily. CMYK only exists for technical reasons, and because of CMYK gamut is so severely restricted we have to deal with its caveats. But that doesn't mean that we NEED to edit in CMYK mode, that only means that we need to be careful and use mechanisms to avoid exceeding the destination media gamut.
Fesco could use those mechanisms better than a dedicated CMYK mode.