Notify All Agents by group versus individual selection

2 years  and still no go?

Not a workaround to be proud of but you could try adding a list address ( say 'staff.support@mydomain.com' ) as an Occasional agent ( so you don't have to pay extra for it ). Obviously, you should not associate such an "agent" with any Group, you should opt for Restricted Access and, if your plan supports custom agent roles, you should assign the "agent" to the most restrictive role possible, in case someone from the recipients of the email list tries to login with the list's email ( which should only be possible if you also have Day Passes available ) or use it in any way. Still, this is just a lousy workaround.