Not expecting this to be addressed but just pointing it out for other users.
I am using the latest beta of Kraken with Openfire 3.7.0 on OpenIndiana oi_151a. When chatting to users on Facebook using the Facebook transport from Spark v2.6.3, everything appears to work great, except if the user is apparently using the Facebook Messenger application:
I have noticed that if users send messages via this application, they do not appear in the destination Spark client. They do appear in the Facebook web browser session itself however. In a Facebook web session, one can identify mobile users by the mobile icon (attached).
I have no idea how widespread this is nor if other standalone IM applications are affected.