Converting standalone instance to Patroni managed doesn't happen with declarative interface

Summary

With pglift, one can "Convert a standalone into a Patroni cluster member". The documentation states that it's possible to do it with the command line interface as well as with Ansible. Unfortunately, adding the appropriate patroni parameters in an instance manifest doesn't trigger any conversion.

Steps to reproduce

$ # create a manifest
$ cat <<EOF > /tmp/instance.yml
name: pg1
EOF
$ # create instance
$ pglift instance apply -f /tmp/instance.yml
INFO     initializing PostgreSQL                                                                                                                              
INFO     configuring PostgreSQL authentication                                                                                                                
INFO     configuring PostgreSQL                                                                                                                               
INFO     starting PostgreSQL 18/pg1                                                                                                                           
INFO     creating role 'replication'                                                                                                                          
INFO     creating instance dumps directory: /home/pierre/.local/share/pglift/srv/dumps/18-pg1
$ # add patroni related options
$ cat <<EOF > /tmp/instance.yml
name: pg1
patroni:
  cluster: pgdemo
  node: pg1
EOF
$ # nothing happens, ie. no conversion
$ pglift instance apply -f /tmp/instance.yml
INFO     configuring PostgreSQL
$ # Using the CLI to convert the instance works
$ pglift instance alter pg1 --patroni-cluster=pgdemo --patroni-node=pg1
INFO     configuring PostgreSQL                                                                                                                               
INFO     stopping PostgreSQL 18/pg1                                                                                                                           
INFO     setting up Patroni service                                                                                                                           
INFO     starting Patroni 18-pg1

I haven't tried with Ansible but I expect the result to be the same.