@dkushari no I don't think you understand me. When I unset driver_node_type_id, it does NOT revert to node_type_id.

Perhaps an example will make it clear:
First define cluster as:

JobCluster(
    job_cluster_key="example",
    new_cluster=ClusterSpec(
        num_workers=1,
        node_type_id="Standard_D4ads_v5",
        driver_node_type_id="Standard_E8ads_v5",
    ),
)

Which results in the expected cluster, then edit to following and deploy again:

JobCluster(
    job_cluster_key="example",
    new_cluster=ClusterSpec(
        num_workers=1,
        node_type_id="Standard_D4ads_v5",
    ),
)

And the driver_node_type_id will stay a Standard_E8ads_v5 instead of reverting to a Standard_D4ads_v5 as expected.