I haven't had success in making that gitlab account. It's probably not possible for outsiders anymore (if it ever was). I have not gotten a reply yet on the linphone-users list either.
Bill has not responded to #984534 either in BTS or in private. While looking through the linphone.org wiki I found the attached PHP script which can be used to run your own instant messaging file transfer server. Maybe you could include it in your changes for the freeze exception next to the READMEs where it can't do any harm. Including it would be nice just to make users aware of the option. Regards, Dennis.
lft.php.gz
Description: application/gzip