Yes. I’m running a cluster of 5 Rock5bs. Runs k3s like a champ.
I’m running Armbian (not Radxa). You have to configure some iptables stuff before you install docker/containerd but other than that no issues at all. See here.
There is a small hitch if you are planning to run Longhorn for clustered storage as Armbian doesn’t have a required kernel module installed (for required to start the iscsid service, which Longhorn uses to present virtual disks in the CNI). I’m not sure if this is or is not included in the RADXA kernel build. I had to build my own custom image of Armbian to get that turned on (not really that hard, but some would find it daunting). I’m planning to offer a PR to the Armbian team to get that module included in the default build.