It would be really helpful, especially for owners who manage lots of teams, if we could send scheduled notifications to ourselves that showed up in correspondence.

We could use this to remind ourselves of all sorts of things that we might otherwise forget (such as calling up a player right before rosters expand so they'll be eligible for the playoffs). I'm admittedly no expert on coding, but this doesn't seem terribly difficult to implement. Seems like you could type a message, select the send date from a drop down schedule, and then do the same with the daily cycle.

Is this something anyone else would use?

Probably but with mobile phone and computer reminders, it's kind of redundant.    If I was worried I'd forget to do R5 protections, I'd plug a reminder into my home computer and my mobile phone.   Typing in one place or another doesn't make that much of a difference.