[wirelesspotat]

Not GP but I have the same set up and have only had a couple times where I received unexpected emails to an inbox. One was from GitHub profile scraping, can't remember what the other one was.

One of the surprisingly useful areas is with deliveries. Emails from delivery companies (especially from abroad) often don't specify what it is they're delivering or who it's from. But with this set up I can easily check that with the email address they're sending to, to know who it's from

[Towaway69]

Can confirm, I'm using the same fastmail setup, same strategy using service@... and no complaints and no spam.

I also use catch-all and no noticeable increase in spam.