I haven't implemented a production Notebook Server environment due to the lack of support for Docker Community Edition on RHEL. However at 11.2 I see that it now supports Docker Community Edition on RHEL 8. We recently upgraded to 11.1 and were planning on upgrading again a 11.3 since its the long term release.
I know you can have different version of ArcGIS Server (as long as they are not the hosted server) federated with Portal, is it supported to have a newer version of ArcGIS Notebook Server federated with an older version of Portal?
No, ArcGIS Server (including Notebook Server) cannot be a newer version than that of Portal. You would need to run through an entire upgrade to 11.2 to be able to take advantage of that system support for RHEL.
Reese,
Can an older version of Notebook Server be federated with a newer version of Portal? e.g. Notebook server 11.2 with Portal 11.4?