Bulk maintenance of notification does not support role related maintenance - if you want to change all users of a specific role you need to find out which users have this role and tick on all users of this role - with view of dozens or hundred of users we have in GB the maintenance of settings is quite time consuming with that limitation (and open to human errors).

Having an additional selection by a role, which implies a search for one role which gives as result a list of any user which has this role assigned. So that at least should be safeguarded since it simplify the update process a lot compared to actual process to find out which users has the roles to be updated by a separate selection, tick them on one by one and do update.

Of course you can think on a more elaborated way of multiple selections, if it is easy to implement. However I wonder about the potential add-on of such sophisticated handling, that you would not have anyway by just implementing the straightforward single selection, that I was talking about. The only add-on I see is to have – potentially – only one selections/updates instead of several selections/updates. In my eyes an oversee able add-on.