"What is of interest to me in the first decade of the 21st Century is: what in digital practice corresponds to contact prints? "
Interesting question, to me at least. Do you mean by what "corresponds" as to the higest resolution, quality of tonal gradation?
I really cannot say i guess, having not tried a wide variety of digital cameras, and having not tried any "medium format digital". I have done 8x10 B&W contact printing though. It and digital are, technologically so different, i think it might not be possible to equate one to something in the other. And in saying that, i am not referring to "quality" aspects in any way. The two processes are very different. Digital is a medium of multiple "intermediacies", more than enlarged film mediums were (in respect to film/contact). Very different beasts.
That said, I find what i can do so far with digital to be exciting, (and this is as to both color and B&W). Digital processing has allowed me control in color, that exceeds the control i had in a b&w darkroom (for me at least. I know with certainity there are chemical B&W printers that do and did exceed my modest skills
With digital, i normally am going for a print. I prefer printing "native" sizes, at usually 360ish ppi, or more, without interprolation or whatever. Being equipment-wise limited to 10mp in capture, i print in the 8x10ish range. Recently, i have been playing arould with HDR software, shooting 5 frames (1 ev apart each) even in scenes that do not have an extreme range of light. In PP i do not go for the cartoon thing, rather, for detail and tonal range. In a way, given the subjects (i.e., stationery, no motion) it reminds me somewhat of when i used to use a view camera.
I am not saying the result is like a contact print. But i am getting a wealth of detail and tonal richness, a dimensionality, that i enjoy.