Since theres the subdomain stripping feature and its working great, is it possible to create a mailbox on a subdomain?

I use the subdomain stripping feature mostly for incoming but sometimes once in a while i may need to send/reply too.

Looking at current user creation menu, its only possible to create mailbox at apex domain, not for subdomain. Since technically zoho already managing email on subdomain via the subdomain stripping feature, why not make it possible to create new mailbox on subdomain too?