I wish Signal would enable this.
> WhatsApp users are getting a long-requested feature: access to the same account across multiple cellphones.
This has been supported by Signal for years by linking devices. You can have the same Signal account on the primary phone (the one you verified through SMS OTP), a tablet and/or a desktop or other device. Messages (and message read statuses) get synced across devices.
Open Signal, go to Settings, then to “Linked Devices” and then choose “Link a New Device” to set it up. And unlike the previous WhatsApp desktop solution, Signal doesn’t (and did not) have the requirement to have the primary phone close by to act as a proxy. You can leave your primary phone anywhere (like on some other network or offline) and still have the linked devices work fine.
Apart from the primary phone, the remaining linked devices cannot be a phone. I eagerly wish this was possible.