@prof. If you re-read the post from @artemus_5 from atma-sphere, you will see that the general rule about higher resistance settings sounding brighter is dependent on the phono-pre not the cartridge. Of course there are many other factors that affect tonal balance as well such as cartridge design, VTA/SRA and tonearm specifics. That being said, with your preamp and cartridge, I would recommend listening to all the impedance settings in the MC mode and decide what you like. You won't hurt anything. When using your MC cart that has low output, keep it on the higher gain MC setting. Enjoy!
-Karl
-Karl