Yes, as above. If you interact with a smiling LAN employee landside you could get caught. They will ask you for proof of residency (DNI or CE – carnet extranjero). BTW being caught isn't so terrible, they still smile (see my post above). But of course you printed your boarding pass ahead of time (best) or at a kiosk so without luggage you do not encounter a smiley face until handing over your BP to board – too late. They may smile at you when checking for oversize bags for gate check, but you'll be sitting at an adjacent place. However, with IRROPS for sure you will be noticed. (Hmm, even if you gate check a bag it doesn't come up – too late).