i was wondering if there is a prefered way to migrate traditonal Clients to Salt.

I want to keep the Channel Subscriptions and Eventhistory for each System and was wondering if i could use the Reactivation Key Feature for that?

I tried it for one system but sadly it didn't seem to work
 # cat /etc/salt/grains
  activation_key: re-1-80fe21d19ee1687bd0c430aa68ed3d06
Do i have to manually reregister each system as a salt client or is there a more 'elegant' or automated way to switch from osad to salt?

Thanks in advance