The standard signal desktop client needs to connect every 30 days, or it will rotate through its keys needing to be reconnected.
Molly for Android, will allow you to run multiple signal instances on multiples Android devices, that might be an option.
You could use a beeper extension, to access signal through matrix on your computer.
If you just need to be able to pass messages between your computer and phone, you could use session, but I don't know your use case