Custom SMTP server for identities in webmail

[msrn]

I have alias email that uses it's own SMTP for sending emails. I would like to use the Roundcube webmail to setup custom SMTP host for different identities. There is already a plugin for this: identity_smtp Roundcube Plugin, that I have used with other RoundCube instances and it works nicely.

Would it be possible to have this for Purelymail Roundcube?