I'm not sure why I'm being downvoted for this, so I guess I kind of accidentally nerdsniped myself here...
Anyways, I did this: https://jsbin.com/teriduyexe/edit?html,output
Which correctly seems to show the EXIF for uploaded images (both in Chrome and Firefox), and correctly filters things in the file picker window. What am I missing, why is this infeasible as a solution?