Molly also has some quality-of-life improvements - such as allowing to enter a device pairing link manually instead of scanning a QR code (thus allowing use in a VM for registration without a smartphone), or being able to use a generic Socks proxy instead of Signal’s own solution. Not only does that allow running Signal over Tor without using Orbot as a “VPN”, but is also more versatile (I wouldn’t want to set up a separate proxy just for Signal, and also their implementation is apparently inferior to some advanced obfuscation solutions).