I stopped as a STH about 8ish years ago,but when I was, it was round by round lock in. Things could definitely have changed though.
I was aksed if i was purchasing the playoffs package by my rep and i said i want them all. I am locked in on the seats for as far as the blazers go but they only charge me once a game/games are confirmed. My last charge was a single game charge fir game six and i have not paid for games one or two of the next round. Once those games are confirmed, im automatically charged. Blazers do it right. Lock you in for all games, but charge as they go. No refunds ever needed.
Foster and Tony Brothers are doing the Philly/ Toronto game. I'll take our crew over that one 7 days a week.
Not to date myself but... Denver doing that reminds me of the '69 playoffs when the Lakers lined the ceiling of the Forum with balloons in game 7 against the Celtics. And then lost. No balloons fell. Bad karma, counting chickens before they are hatched.