@nephros has suggested a number of mechanisms for getting jabber/xmpp data associated with contacts: here XMPP no longer works - #6 by nephros and reading the thread may be instructive. Also see: No 'presence' in 'settings' app on pinephone
I’ve actually been able to use the native messenger to XMPP but find it really ‘odd’. I don’t actually use Shmoose, but it does work. It’s just not integrated into the os.
And, as @phklrz mentions, no omemo in the native implementation. errr. that’s no good.