How about adding some well made extension tubes to the R system while you're at it. The R system is still lacking some very basic things that I have always taken for granted and have been available to most camera systems since I began my photography over 40 yerars ago.
I suspect that extension tubes were never very popular, and they're likely pretty far down on Canon's priority list for the RF mount. I think they're of even less importance considering that Canon is adding semi-macro capability to many lenses that would have formerly have been used with tubes, e.g the RF 24/1.8, 35/1.8 and 85/2 all go to 0.5x native magnification.
I do have the EF versions of the 12 and 25mm tubes, which I use mainly for closer focus with the 600/4 II. Although I was not inclined to trust a 3rd party tube as the bridge between a $13K lens and a $6-7K body, for what is probably a more typical extension tube use case (increased magnification for standard lenses) a 3rd party option would be fine. There are already several of those for the RF mount, e.g. Vello (12 + 20 set), Kenko (10 + 16 set), Meike (13 + 18 set) and Fotodiox (15 and 35, separate).