I think the original request is similar to what I'd like to see: more control over specific types of notifications.
The original request is asking for only error messages to be displayed as alerts, but the suggestion to change it in System Preferences would make *all* notifications as Alerts, instead of just error notifications. I'd like to do this too.
I'd also like to see the ability to make only my custom notifications be set as Alerts, with all other non-error notifications set to Banners.
Actually, I'd really prefer to be able to specify this in the action, on a per-rule basis.
The ideal situation (for me) would be where general alerts show up as auto-dismissed Banners, error notifications show up as Alerts, and the custom notifications can be set to show up as Alerts or Banners.
The ability to choose between Alerts and Banners for custom notifications on a per-rule basis would be even more ideal.
I'm sure others would have different combos. Would be nice to be able to have more control over how each are displayed.