[BozeWolf]

I run signal on my phone, tablet and computer and they all are synced.

[tcfhgj]

Actually, they just receive the same messages.

According to my expectations, resetting your computer app and data and reconnecting to your account should result in an more or less empty message history.

[attendant3446]

The last time I added a new device to Signal, I was given the option to sync old messages. Not all of them, but I think it was the last 60 days, which I think is enough.

[kdmtctl]

It does sync some timeframe in the recent versions.