As a replacement of the standard mounting plate of the Epiquad, I designed this camera mount. Just use the 4 screws to attach this seat on the front of the top plate.
As an extra, use the plate to protect you xiaomi yi action cam.
EpiQuad 210x - https://goo.gl/RGmMhI
EpiQuad 180X - https://goo.gl/KwPkPo