dovecot - Sep 2019 - Namespace structure

Is the following "legal" for Dovecot? And...is this separation 
recommended or a bad idea? Particularly I'm asking about the
"archives"
namespace - I haven't actually implemented this yet and I'm checking 
before I break something.

10-mail.conf

# Primary private namespace
# Using sdbox for storage
namespace inbox {
   type = private
   separator = /
   prefix    location = sdbox:/var/mail/%d/%n/sdbox
   inbox = yes
   hidden = no
   list = yes
   subscriptions = yes
}

# For long-term archival
namespace archives {
   type = private
   separator = /
   prefix = Archives/
   location = mdbox:/var/mail/%d/%n/Archives/mdbox
   subscriptions = no
   list = children
}

# Shared mailboxes
mail_shared_explicit_inbox = yes
namespace usershares {
   type = shared
   separator = /
   prefix = shared/%%n/
   location = sdbox:/var/mail/%%d/%%n/sdbox
   subscriptions = no
   list = children
}

# Virtual mailboxes - for server-side searches
namespace virtual {
   prefix = virtual/
   separator = /
   location = virtual:/var/mail/%d/%n/virtual
   subscriptions = no
   list = children
}

-- 
Daniel