I believe the wording in the WPA ruling goes something like "If the piece of equipment is not listed in the rules, it must be presented to the tournament director/head referee before the tournament starts for approval". This is not in my opinion a standard bridge head, so I think it should get approved before the tournament.
If my opponent would pull out that kind of a bridge head, in a weekly tournament I'd probably say nothing but in a bigger tournament I'd sure ask the TD if that is legal before letting my opponent take a shot with that. Funny looking gimmick though and probably useful