Hi Bo,
I can't predict for the IMMORTAL, but with the NARUKE ACURACY in the same configuration, I never had issues with the ESC.
We had 34 °C yesterday in Paris, and I flew 7 rounds with no ESC problems.
I'm just cooling down the engine for 10 mn after the flights.
As you can see, both engine and ESC colors changed ... after 1631 flights ...