Engine Braking Calculations wrong?

Hello! I'm trying to make an F1-style hybrid system, and it's mostly working, except the throttle mapping is a little bit broken because of the engine braking.
I feel like that's actually one of the last things i have to fix to get it ready for release. I hope someone can help me, or tell me where to report this

Setting the engine's maxPowerThrottleMap to 0 gives a 1:1 torque map, but the maths for engine braking have a weird behaviour.

The maths in combustionEngine.lua are like this:
engineMaxTorque = torqueCurve[rpm] - friction
requestedTorque = torqueCurve[rpm] x throttle
engineLoad = max( requestedTorque / engineMaxTorque, 1 )
engineBraking = engineBrakeTorque x (1-engineLoad)

That causes a problem because now the engine can reach 100% load before getting to 100% torque, because it is dividing torque over torque minus friction
https://www.desmos.com/calculator/8n6hadq43q <- Here i plugged the data for a stock Sunburst engine @ 5000rpm aprox, and added the "fixed" version of the engineLoad calculation without the friction

If i change line 712 from combustionEngine.lua to not substract the engine friction on the load calculation, then the throttle map is fully linear, and it works perfectly, but i would reeeealy prefer to not step over a main game lua file on my mod

Is this expected behaviour? Should i not b*tch about a ~1% delta in my throttle mapping? Or should i actually try to invert all those equations to make a throttle map manually without touching the maxPowerThrottleMap?

Thank you!