dovecot - Mar 2021 - How can I migrate mailboxes after changing hierarchy separator?

Hi,

I had a common problem (folders can't contain dots) and the obvious 
solution seems to be changing the hierarchy separator and using the 
listescape plugin.

My question is: Do I need to take any extra steps after changing the 
separator to migrate my existing mailboxes? If so, which?

I tried just simply renaming the folders and doing a `doveadm 
force-resync` but that did not work as intended. Afterwards I wasn't 
able to subscribe to any of my folders, so I guess that isn't the way to go.

Kind regards
Simon