if there is a csr signing file /etc/puppetlabs/puppet/csr_attributes.yaml on any of the infra nodes it will merge it with the peadm specfic csr attributes https://github.com/puppetlabs/puppetlabs-peadm/blob/501aa363c5bd60f94e5931cead6cdfe2349b6856/plans/util/insert_csr_extension_requests.pp#L2