It's the same principle as someone powering up to lvl 30 or so, checking the "easy" spots they don't have and seeing if it's there.

The difference is, in this system people have incentive to continue ranking up without their wands (as it increases the likelihood of it triggering at a given spot).

The only potential downside to this idea that I see, is that it might make low lvl mages weaker, in that it's harder than normal for them to find their wands (though still extremely possible). But I'm not sure how that'd pan out.

Maybe make aura and shield still relatively easier to trigger at low lvls, but barrier is more unlikely until they get higher up?