[tptacek]

Getting messages to flow across lots of different platforms for a single account has been a source for a number of very bad security problems in other messengers. (Recent example: Matrix, Nebuchadnezzar). Different projects, different priorities.

[JoshTriplett]

Signal already has the ability to register multiple devices with the same account, though. The only thing they haven't done with this is support sync of past messages. That seems like it should be much simpler than supporting multiple devices in the first place, and I'm wondering if there's some non-obvious attack that they're simply not talking about or if it just hasn't reached the top of their priority list yet.