This is the official answer from Shure if interested
Copy / paste:
Q:Can the SFG-2 be used with moving coil cartridges, or only with moving magnet cartridges?
A:We only speak for Shure cartridges - all are moving magnet and work well with the SFG-2.
Q:It is my understanding that the magnets in moving coil cartridges are powerful enough to attract the stainless steel balance beam of the SFG-2 and produce incorrect readings.
A:This is feasible, though we have never tested the theory. Most phono cartridges use Mumetal for the cartridge body; MuMetal acts as a magnetic shield, thus shielding the internal mechanism from outside magnetic influence and vice versa.
FYI - Stainless steel has no, or very slight, magnetic properties.