Sonnie had claimed about 15 stops DR which might make the best digital film
for OMZ lenses in this regard. It has the same sensor as OMA7rII which I have
I think the clipping point is non-equivocal but the lower end depends on who is
measuring and what criteria for a usable signal.
Photons to Photos has a good handle on this and perhaps more than DXOmark.
I don't see 15 stops there. Nonetheless on comparable images (at least a few
I've seen) there is a tad more detail in the shadows. Sonnie claims improved
Themed Olympus Photo Exhibition: http://www.tope.nl/