I'm reading through this thread and can't help but think saleen is searching for a solution that doesn't have a problem. I'm a Sunday Ticket sub and I've never once tuned into the Game Mix channel. It could be removed from the lineup and I wouldn't care. Same goes for the Red Zone Channel.
I subscribe because I am a Cowboys fan living in North Dakota. If I'm lucky, I might get to see 4 or 5 Cowboys games a year without ST. Everything around here is Vikings, Packers and Bears.
The mix channel has no appeal to me because when I'm watching football, I tend to concentrate on one or two games. If the boys are playing, the channel doesn't change until halftime or the end of the game.
With the exception of some diehards like the ones who have posted here (nice setups by the way!), I would imagine your average NFL fan probably has similar viewing habits to mine. I guess the point I'm trying to make is the mix channel has limited appeal, and if this was really as big a problem as you seem to think, measures would be taken to limit the impact of blackouts on that channel.
The mix channel is a nicety. And pretty much hard to watch except when 4 or fewer games.
But to each his own.