As far as I can find, 2.0.6 is the latest version. Just remember, firmware is for the camera, so all you really need is the *.FIR file that's in either the dmg or zip file. So, if you can't find the Mac dmg, just change the the OS on Canons support site to Windows and download the ZIP file. I think Mac will handle zip. I just found it under the Windows option, so it is there. But you have to keep clicking "Load More" until it shows up.
Newton
EOS R5, R6, R6II. RF 15-35 f/2.8L, 50mm f/1.2L, 85mm f/1.2L, 100mm f/2.8L Macro, 100-400mm, 100-500mm L, 1.4X.
