Also, according to the lt250r manual:
- less then 1/2 throttle for up to 10 hrs
- Do not maintain constant engine speed for an extended time period during any portion of the break-in. Try to vary the throttle position.

So maybe letting it idle for a long time is not the best idea?

No not a good idea.

Less than half throttle for up to 10 hrs?!? I might do one heat cycle if it's running good. Then it's WFO!