Is there a way to set default annotations on nodes like you can do with node-labels in

/etc/rancher/rke2/config.yaml

? I need to set

<http://k8s.io/cluster-autoscaler-enabled|k8s.io/cluster-autoscaler-enabled>: "false"

on all of my nodes besides the ones being managed by the CA

no. the labels stuff is built into the kubelet, we just pass the configured labels along and let it do the work. There is no equivalent for annotations.

So aside from adding something like

kubectl annotate node <node-name> <http://k8s.io/cluster-autoscaler-enabled|k8s.io/cluster-autoscaler-enabled>: "false"

to the user-data script for those nodes, there's really no convenient way to do this?

correct. You need to use some external tool to set node annotations.