I run "Normal 10" on my Medusa. I've read some folks have had trouble with lower timing on these. Seems like folks running CC and Nue motors aren't having trouble with lower timing.

Medusa's website does say to run it at 8-15 degrees timing for max efficiency so I would just run them within this window. I might experiment just for the experience to see if the motor temps increase with different timing but of course I would monitor closely. If I didn't see any performance difference outside of that recommended window though I would still be inclined to set it back to within that recommended window after the testing.