Can't group scheduled Android notifications without grouping per new notification

[auradigitaldev]

I'm trying to group scheduled notifications, but am having issues because AFAICT the only way to group scheduled notifications is to schedule a notification with setAsGroupSummary=true. When a new notification is delivered I want it to be added to the group (if it already exists) or create a group if none already exists. However, I don't see a way to do this with scheduled notifications other than scheduling a group summary notification for every standard notification.

Let me know if this makes sense, and if there are any workarounds!