This worked fine for me, just some small extra steps.
Made a full backup on the master node.
Disabled all notifications and then started with a single distributed site first.
I then did a site copy, just in case.
As no config conflicts were detected on the first distributed node I just updated the rest of the distributed nodes.
And lastly the master node.
Let everything settle down, I had to re-inventory a few hosts that were using piggybacked k8s data (Guessing due to Werk #11263)
Then I re-enabled all notifications again.
Would be nice if https://checkmk.com/cms_update.html had a section with a note on recommendations/steps for distributed setups.
And perhaps a matrix showing what versions are backwards compatible and not.
Maybe there is such a page somewhere and I’m just missing it?