Unblock Toast notifications on Intune multi-app kiosk

I have a system utilising a multi-app kiosk delivered by Intune. The default settings block any and all Toast Notification popups. The system is for a Library setting and the library management system (Libki) session time reminder notifications are being blocked.

I have tested the app on the same device without the restrictions and the toasts are displayed without issue. I have so far found a great number of registry settings that have unblocked the notification settings in various blades in the Settings app, and outwardly it looks like it should be allowing the toasts. However, when running as the unrestricted account, the Settings>System>Notification & Actions shows the Libki app in the "Get notifications from these apps" list. When logged in as the kiosk user, that list shows only the "Tablet mode" app.

I'm aware that there is an SQL lite db in the local appdata folder that has some interaction with the registry settings in HKCU\Software\Microsoft\Windows\CurrentVersion\Notifications

but have been unable to get Libki to populate into the list in Settings. I suspect that that alone, or in combination with the resultant options that should be available to me thereafter, will probably allow the notifications.

Any help would be greatly appreciated.

Martin