Included below are many excellent resources spanning the philosophical and practical that cover equity and representation in open pedagogy and OER, and can serve as a starting point for learning more.
"Framework for Reviewing Inclusion, Diversity, Equity, and Accessibility in Open Educational Resource"
"Equity, Diversity, and Inclusion in OER"
Lambert, S. R. (2018). Changing our (Dis)Course: A Distinctive Social Justice Aligned Definition of Open Education. Journal of Learning for Development, 5(3), 225-. https://doi.org/10.56059/jl4d.v5i3.290
Editing openly licensed texts is possible whereas that is not the case with print commercial textbooks and commercial digital materials. Below are some sources to get you started with process.