It’s a shame because it is possible - I used the old e23 image and custom dtb from here: Taco + CM3 not seeing m2 SSD nor SATA drives this gets nvme working on taco + cm3
At least that gets me a working board but on a very old image and an old 4.x kernel.
I did spend some time trying to work out the differences between the e23 custom dtb and the one used by the radxa-cm3-rpi-cm4-io images - best I can tell is there is additional 3.3V routing to the nvme slot required but I haven’t been able to get it to work yet.
My current plan if no official image comes and I need to update will be to replace the radxa cm3 with an rpi cm4 on the taco so that I can get supported updates.