@holziholz my work on the EA7500v2 did not progress much. I reverted back to the opensource WiFi drivers as the close sourced binary drivers are clunky to use. As the open source drivers are also not ready for prime time, this project of mine sort of got sidelined. The last time I tried was probably 6 months ago.
My EA7500v2 is currently collecting dust at the moment tho.
Maybe @jackcolentern has a working build for the EA7500v2 as he seem to be more active compared to me in OpenWRT thinkering.