I had vaguely recalled that as well. I guess there is no profit in providing a firmware update and quite a lot of work…..

ROON Rock on an NUC across the systems
Sitting room: 218, DSP7200SE
Study: 218, Quad 303, Spendor BC1
Bedroom: Musical Fidelity A3CR, Chartwell LS3/5a
Various Sonos boxes in bathroom and spare rooms