Certainly! It's actually 90% there already. All incoming packets are handled the same way regardless of the sender. The JS does this by querying DOM for a div with the "fbChatMessage" class but without the "read" class. Once it has this div, it processes it and then marks it as read by adding the "read" class. It does not depend on which chat box this div lives in though, so if you received 50 packets from one friend and 50 from another (and they had the same UUID and filename), it would compile and display as normal.

The only challenge would be dividing up the packet requesting, but you could do this manually by pasting in two handshake packets, one with startat at 0 and the other with startat at 50:

{"handshake":true,"uuid":"somethingRandom",type:"whichToSend","startAt":0,"filename":"nyancat"}

{"handshake":true,"uuid":"somethingRandom",type:"whichToSend","startAt":50,"filename":"nyancat"}

And then boom! Receive as normal and enjoy your ultra-slow bittorrent-style bandwidth

even better, but I know there were huge efforts to detect these type of transmission and block them entirely. If you're with comcast you probably know about it. Many providers use deep-packet inspection now! :(