I have them on the left side of an EH3 (added later) but I have sling swivels under. The forend had 2 swivels that I removed then used a short pic rail with integrated flush cup on. The pic rail cup works well enough for me with the left side rear cup that I never added one under the rear.
Offhand, I think there is enough stock through the forend for cups...pending barrel contour inlet.
