"how to handle this question correctly"
I'm pretty sure it's a "yes" or "no" type of question......call me silly but why has this question turned into the type of question that we have to "handle" and "tip toe" around?
Do you use a mix? Yes or No
Pretty simple one word answer is all that is required.
If a sales person starts giving me a "song and dance" answer to a "yes" of "no" question......that completely turns me off.
The only people placing the "stigma" on mix bakers are mix bakers.....please get over it, this topic is so old and beaten.
So to the OP when you're asked do you use a mix answer yes or no. You don't need to defend your technique....be proud of what you do whatever it is.
This deserves a round of applause.