Is it possible using the mgt-person component to output the value of the presence activity string (e.g. "OnAcall") as one of the line property values?
Example below - see line2-property example:
<mgt-person person-query="someone@something.com" show-presence view="threelines" line1-property="displayName" line2-property="Presence.Activity???" person-card="hover"></mgt-person>