I was a happy user of this tutorial. I recently discovered that with Proxmox 8.1 a new notification system has been implemented, which supports configuring an SMTP endpoint to send emails (rather than having to configure postfix to relay via a preferred SMTP endpoint).
So here's my journey in...
+1 got the same error. It would indeed seem useful to update the defaults. Also, as of now, if you don't pick the "daily at 0:00" you can only pick the "daily at 2:30; 22:30" which actually seems to run the task (either prune or GC) twice. Having a "daily at 22:30" option by default would likely...