So, small update (sorry, I meant to post a few days ago but totally forgot): at least for multi-node, there is no value. Meaning, if you set a value, it will be that value, but if you don't it will be multinode. So if you, like I was, are setting up cluster policies and you wanted to, e.g., set single node as default but still allow multi node, you'd set spark.databricks.cluster.profile as singleNode, but set it to be optional. Can't remember the syntax off the top of my head, but it's along the lines of isOptional: true. Maybe not what you're looking for exactly, but that's what I needed. Good luck!