Sorry for the delay in responding.
My question is, can we send the initial global settings to a group / Role ?
I’m not entirely sure I understand your question, but I’ll try to answer nevertheless.
bbpnns allows you to configure roles for notifications. The BuddyPress bridge add-on for bbpnns will allow you to notify all members in the author’s group or all groups that have access to the forum.
My second questions is, can the notifications be configured to send a digest of only the forums / topics a user has subscribed to or is is all or nothing
The bbpnns Digest plugin will send digests to whoever should have received notifications given bbpnns’ settings. If you configure bbpnns to *only* send notifications to forum/topic subscribers, then the Digests plugin will send the digests to those users. If you configure roles/groups, it will send to those as well. The Digests plugin only assembles/sends the emails, it doesn’t control to whom – that’s bbpnns’ job.
I hope this answers your questions.