Are you all thinking about, or planning to allow plugins? eg say I wanted to use jmap to implement some of hey's functionality -- for instance the screener tha

Are you all thinking about, or planning to allow plugins? eg say I wanted to use jmap to implement some of hey's functionality -- for instance the screener that isolates and allows ban of new emails on first contact. Rather than a client, can I have a server that listens to my fastmail inbox and (potentially) moves emails as they're delivered? Any chance you're thinking about allowing UI space for things like that?