Just to clarify, I might be misunderstanding what you mean when you say you don't like mixing meso and thermo MCs. I thought you meant, you don't like mixing a starter culture that is a blend of meso's, thermo's. For instance, MA4001 would be a poor candidate, because its inevitable that you would be screwing up the ratios when culturing up a blended starter.
Do you mean, you don't like mixing MCs in a vat - as in a meso MC (MA011), and a separate MC (ST), added in together? Or, if you're really inspired, culturing up 3 separate MCs, MA011, ST, LH100, and adding them in together. Multiple mother cultures, inoculated separately, in other words?