https://puppet.com/docs/pe/2021.7/upgrading_pe.html#upgrading_pe There's some warnings about disk space due to the postgres upgrade and warnings about agent support that's been dropped but I know customers have gone through the upgrade and it works fine. Making sure https://forge.puppet.com/modules/puppetlabs/pe_status_check checks are clean really helps. If you use PEADM you can use https://github.com/puppetlabs/puppetlabs-peadm/blob/main/plans/upgrade.pp to make it even easier and a lot of customers are taking that on now. PEADM has a convert https://github.com/puppetlabs/puppetlabs-peadm/blob/main/plans/convert.pp to take on non-PEADM managed infrastructures too,