Yes Erik, if the Group Latches just worked like a traditional VCA/DCA Group, all of this would be a moot point and SAC would be 10 times better of a product in my opinion. If these worked like real DCA groups, then you really could use the monitor mixers like matrix mixers. As it stands now, I still use them that way. You just have to be really careful about what you're doing.
What I have been doing a lot lately is chewing up Aux Send/Return channel, using those as Submixes. Then I can take those feeds to another mixer and use the outputs on the monitor mixers as a matrix output system. The drawback to this of course is that then if I want to apply reverb or some other effects like that, I can not do that with the channels that are submixed down to an Aux Send/Return because you can not route one Aux to another Aux. So I have to pick and choose what I want to do.
Using Output 9-24 as Submaster is OK for me sometimes as well. One of my biggest issues is that 8 stereo outputs is not enough outs for me on larger sound systems, not even enough to properly do just the house speakers. For example I am using SAC as our mixer and system processor at Idaho Shakespeare this summer. That system has 19 outputs (Or 8 stereo pairs plus a mono sub feed and 2 other feeds which can not be operated as a stereo pair) just for the mains and surround speakers. That doesn't count any on stage speakers, hearing impaired feeds, etc.... So it can not just all live on the FOH mixer with it's 8 mono or stereo outputs.
Or if he just did the custom fader layer he promised that would solve my issues as well. Then I could just drop in any channel strip I like from any mixer I wanted and put that on a handle on a control surface.
Either of those are workable solutions for what makes me grumble when working with SAC. I don't really care which one, he only had to do one of those two things and it would make at least 50% of my complaints about SAC disappear.