I was wondering what you think about max ERS cause if you upgrade the ERS part of engine r&d you in race your ERS will not drain below 40% so it's no need to disable it. And even if your engine is e.g 5/6 in the graph due to large recharging the loss is minimal cause you have ERS always on the OV mode
You positive you're able to run the whole lap with OT on though? I wouldn't be surprised if those crazy harvesting rates were happening majorly due to a more efficient MGU-H.
The MGU-K has its limits though and you should never be able to deploy over 4MJ on a lap. No matter how good your MGU-K is, when you activate the Overtake mode it should still work at the maximum of 120kW (I think) rate.
Basically, how much juice will be left on the battery will vary depending on your R&D status, but a bad car and an outstanding one should still deploy the full 4MJ under the same 30 or so seconds it takes with the Overtake flat deployment rate.
Edit:
Can I send you videos too, you naughty? 🙈