Damn...you're right.
I guess I was thinking that instead of following her easily-trackable-by-bad-guys compass toward the treasure, she could head off in a random, boring, non-plot-critical direction. Make direction readings all along the trip, triangulate the actual treasure location in a whiteboard trigonometry montage, and inform her Perfectly Trustworthy Comrade. PTC could then go get the treasure at his/her leisure, since the bad guys' tracking gizmos only target the protagonist.
But I forgot to think like Elan. Once Protagonist heads out on some path, it's no longer a random, boring, non-plot-critical direction. It's the direction she actually went, and all sorts of complicated dangerous stuff will happen there. And then after she deals with all that, PTC is still gonna betray her.
Poor Protagonist. I hope it's a particularly shiny treasure, after all the improbable crap she'll have to endure for it...