I never had an issue with loosening. I'd give it a quick pass over a sheet of sandpaper on the counter top, and a smear of Threebond 1184, and get the screws plenty tight. You may still need/want to slot or enlarge the manifold holes to fine tune the position. I haven't done a QA, but on the Zed, it's nice to run the cable in the narrow gap between frame and tank.