One way is universal screening with a non-verbal test. I do not know if the alternate tests are comparable, but it certainly removes some of the biases. In our area, almost all of the schools rely on parent or teacher nominations for testing. Even highly capable parents that were raised in a different educational system may not know how to get their DC the support and assessments that they need. One local district has tried this approach and is seeing dramatic changes in the representation of lower SES and other under represented groups. See an article here:
https://www.seattletimes.com/educat...ersal-screening-to-find-gifted-students/

While simply finding the child and learning what they may need to achieve optimally is good, it does not solve the problems of equal access, equal opportunity, or the other impacts of lower SES. It is, however, a small step along the road that may lead to better outcomes. Universal testing may also impact all aspects of our failure to provide an education commensurate with the needs of the individual child.