Technically, yes, everyone who will use the tickets is supposed to be present to activate them at the ticket booths. Most of us will bend that rule a little if someone's spouse is stuck in the bag check line or taking the kids to the bathroom or something like that, but we're supposed to see X people if we're activating X number of tickets. Again, I don't know what Shades of Green does.
I don't scan MBs to activate Salute tickets even if they're already linked, but some CMs do. Personally, I find it a hassle to have a big group of people all trying to align their bands properly on the scanner. I swipe each paper certificate, pull up the
MDE that it's linked to, and assign a plastic card to each person, then activate the certificates from there. It sounds like a longer process, but it's really not, and it works better for me. To be honest, though, I see a lot more Salute certs that aren't linked to MDE at all.