I have added some test OL 7 clients to Foreman using the Subscription manager / repo workarounds. All good and connected fine. I am noticing that the check-in time on the content hosts page has not changed since they initially connected in.
I am reading that this could be due to rhsmcertd but would like to confirm here if others have noticed similar behaviour and what the fix was. Also if this check-in time is actually related to puppet because we are using Foreman with Katello and wont be using Puppet in this env.
If I am not wrong, the content host check-in time is from when it uploaded its last package- or trace-report. So it is independent from Puppet (or other configuration management solution) which would be the normal managed host object.
You could verify this by running a dnf command to upgrade/install/remove a package on a content host which should report back the installed packages.