... or maybe I should just get a dedicated mixer module instead?
Probably the right move. Consider: a proper performance mixer offers VCAs for audio levels, panning, usually AUX levels, and sometimes a CUE bus, headphone preamp, metering, etc etc. Yeah, something like a Toppobrillo Stereomix2 is $400+...but it's got at least $400 worth of submodules hiding inside. However...
...and the CWEJMAN VCA-4MX QUAD VCA MIXER.
-- joesh
To have that module, you'll need sufficient money to afford it...and also, to afford a time machine to go back about ten years, as Woja's been dead for a hot minute. But by and large, charging brain-wrenching prices for stuff like that is more about...ah...well, why do people buy Ferraris when they KNOW they'll mostly be driven from home to the service garage and back again? Same idea...you're paying for a name when you really just need the module. Save your money.