Atorch DLB-600W DC load

[Odd]

Hi, I purchased a DLB-600W from Atorch on Aliexpress.

The load can be connected using kelvin probes.
I heard a loose part inside - it was a 1cm wide 6-turn coil on 0.9mm wire. it's resistance is 50mOhm
Atorch support told me it was mounted internally between I- and V- inputs as a "reverse polarity protection"

Having it there clearly destroys half of the precision gained by having sensing leads.

1. Does anyone know exactly what it is supposed to protect? - I can only assume it is against connecting V- to V+ or so.
2. if you have one, and do not remove it : do know that the precision is compromised. - the factory calibration of the device is otherwise very good.