There are 4 FX units, and two dedicated FX mixes.
You can use other mixes to provide ‘FX3’ and ‘FX4’, but you lose the monitor mixes.
If you are apply FX to a single channel then you can also use Channel->Return.
The Returns from each of these have their own faders, so the wet/dry mix can be changed on the fly quite easily.
If you use all 4 expects returns, rather than Channel-Return (insert) option, then you could put them all in the same mute group, giving instant 100% wet/dry comparison.
to accomplish what you are asking really requires a Digital Audio Workstation (DAW) program like Digital Performer, Pro Tools, Logic, Sonar or some other program to make automation changes for each mix. That is the best way and offers the most flexibility, the Qu mixer on it’s own does not have automation like a DAW.
Are you wanting to have 3 different Scenes, as A&H calls them? If so, all you have to do is use the FX mutes to remove all effects.
On the A&H console, a Mix is the name used for Monitors. If this is what you mean by “mix” you may have to use a different approach, as previously suggested.
You can save many “scenes” that include all parameters including effects, then change the “scene” as the music plays while you are mixing. But as was mentioned, there is no automation of motion- you must use a DAW to record your fader or knob movements.