My impression is that you are trying to be racially sensitive or politically correct. You are using terms like DEI and saying it is important. But what you are writing comes across as very racist. "We have to have a black person on the team because black people think different!" No, your race and gender don't determine your beliefs or perspectives.

The way to find out what different groups will think about your product is to survey representative samples - not to hope that the person of background X on your team could speak for all X.

You can use focus groups for issues you don't know about - absolutely. That's one of the main benefits. Get a group to use the Go store. Ask about what they thought. Ask the people who used it a lot and those who used it a little - why did you use it so much/little. You find that some people are made uncomfortable because it feels like stealing. There - if you didn't realize that was an issue before, now you do.