Ok

I understand what your thinking, but the idea is the duvolle is a scout catcher, that's what it is meant to do.
This doesn't make the scanners unbalanced, the way scanners work is unbalanced.

1) Once you scan, you can switch back to your light weapon
This is problematic because there is no negative to doing a quick 360 and the getting intel for the next 30 seconds

2)Scans 'Tag' players physically showing there tag to 100% accuracy, 100% of the time
This is problematic because having THIS much intel without a drawback is a little unfair

3) Tagging lasts for ridiculous amounts of time
4) Scans have incredibly long ranges

Ideally I think scanners should work more like the movement detectors in ALIENS.
The scanner sends a pulse intermittently that 'tags' the player, but this tag is only updated with each pulse
Furthermore as soon as you change to a weapon or other equipment the tag data is lost

So you might choose a short range scanner with moderate prescision, that comes with a short interval to give full real time info to a squad.

Or you might go for ultra long range moderate prescion but with an incredibily long interaval, which would serve more as global battlefield intel, such as where you predict groups are moving to.

As for being able to detect scouts, there should still be one, but it is only short range, moderate interval and incredibly small FOV