I'm guessing that the text messages could give hints about our opponents so we can figure out who and where they are? You'd have to be smart to figure out clues, making having the items that locate them still useful but not like they'd be the only one who can know where other people are. Or it can be like Sword Art Online in one battle they had where every certain length of time it showed everyone's pinpoint location for a few seconds before going away. Everyone could have this item, only the enhanced version going to one person.

Searching the heel would make sense if the character knew (or at least strongly suspected) she had something on her but couldn't find it elsewhere, but your point is still valid for in general.