Maybe @Androidlad you ll be able to answer.
I have the Sony A7III and the Atomos Ninja V.
I made a test this afternoon and I can't figure out what it's happening.
I set my Sony in hlg3 picture profile.
I record first internally, then I record with the Atomos ( Atomos without matching camera and hlg) and get the same result.
Then I switch the Atomos in HDR input and switch CAMERA OUTPUT to the correct brand Sony the Correct Gamma HLG and correct gamut BT2020.
I let the monitoring gamma to native and the record was the same as the 2 first