Hi Bruce, I appreciate you taking the time to reply! 
It is true that you are patching exploits that are found (like you did in August). So I agree that even though the situation of using dead kernel + dead OpenWrt is not perfect, it's better than "it's 700 days old and nothing has been patched at all".
And yes, I agree with you that the closed-source driver should not be the only driver in the op24 branch, but I was suggesting an extra branch "op24-closedsource" where we can test op24 snapshot with the closed source driver. Existing separately from the normal, open-source "op24".
This possibility depends on whether the Mediatek SDK can be compiled on the kernel that op24 uses, of course. But if it can be done, then I'd love to try using it until the open-source driver becomes stable.
Right now, the thing stopping me from installing "op24" is that people are still saying that WiFi becomes weak, slow, and stops working after some days when using the open-source driver. Examples here from the latest 4.7.0-op24:
I really hope the issue is solved sometime this year, so we can all move on to fresh, maintained versions of OpenWrt.