Its hard enough with a non dji extender. You need to make the wifi module a dd-wrt router. This is not possible as you need 8mb of ram for the router software alone. Then you need to set up wifi bridge client and mimic the 10.0.5.9 ip that the gopro is configured on.
Ive done this on an asus with the ddwrt flashed firmware and couldnt get much range. There is also massive lag which makes fpv flight impossible. And also, the gopro app will just freeze with the last image and will not black out to tell you that you have lost connection.