Ring group shared voicemail

I've gone with a "ring group", but I lost the ability to have shared voicemails. I had shared voicemails with "call queues" (after a lot of work), but dropped the "call queue" because there's no call waiting with call queues (a 2.5 year old request is outstanding). I found a page describing how to have shared voicemails during closed hours or if you put the phone on forwarding, but there's not a way to have shared voicemails for missed calls during open hours.