Sorry it's taken a while to respond to this one.
Currently, the records which generate the notifications (which live on the form AST:Schedule View) are only created once assets are related to the schedule. So for now, it'd need customization to set this up to notify on non-asset-populated schedules.
I hope this clarifies, apologies for the delay in answering.
That's alright, thank you Jon for confirming. We decided to just make sure all our schedules related to an asset, even if it had to be a 'dummy' asset like 'G type monitors' or something.