i think its more of an airport policy thing
when i told the agent that ive read that front of the line benefits can be extended to wife/kids, another hs agent overheard my question and reiterated in no uncertain terms that if i were to attempt it, my membership would be immediately revoked
lax is known to have different customs policies as well in regards to bringing in esrogim from israel, that even with a sticker, they wont let it through. might not be related though