The design function of that cross member is to keep the arms at the proper spacing. While it may very will function as a solid lift point, if you happen to bend it your QA face plates will not work properly since they will no longer be parallel to the vertical axis and may well be canted toward each other on the horizontal axis as well. I don't think the FEL can lift with enough strength to bend it, but I wouldn't do it. If you really want to put a hook there, put an extra plate or piece of angle iron almost full width on there to reinforce that crossmember instead of just welding the hook to the tube. -- BTW, my father-in-law accuses me regularly of overbuilding things, but I haven't broken anything yet, either.