Hey bud. With my limited experience with brushless, I did the same as you, asked and listened. You'll find it much easier to learn at the track once yours opens.
Sensored brushless motors will "thermal" at some temp above 200'F. In other words, the speedo will shut down when it sees motor temps hit a preset value. You've probably got a temp gun from your nitro program, bring that with you and temp the BL motor after every run. Fiddle with gear ratios to get as close as possible to the appropriate ratio that your motor/track-layout calls for, and use the 200'F mark as a high point.
Since I just got into BL as well, I'd be keen to hear what temps others are seeing and feel safe running at. I chose 200'F after hearing about a 225'F meltdown from another racer with the same motor that I have.
p.s.-Don't forget to set the lipo voltage cut-off on the LRP Sphere! It's there for good reason.