No updates as of now - as an additional workaround, have you looked into writing a message (note without parent) to the user? This should trigger a notification
note = session.create('Note', { 'content': 'hey', 'user_id': author_user_id})
sesssion.create('Recipient', { 'note_id': note['id'], 'resource_id': target_user_id })
session.commit()