Most cars have a idle speed that's higher when the engine is cold, so why not implement this too in Beam?
Most people playing this game probably don't even know you can have a cold engine, so time used for implementing such a miniscule feature could be spent on something else
The coldest spot among the official maps barely goes below freezing and pretty much all the IRL effects of cold components are not implemented at the moment: Weaker battery amperage Engine wear and tear due to cold oil. Freezing of coolant. Greater pollution due to cold catalyst media. Brittle plastic parts when really cold, contraction of materials, etc. Engine thermal features could use a little work, modern heat exchange mechanisms between oil and coolant are another notable absence. That said, the end effect of dynamic idles could have another use. To recap, one portion of modern electronic stability/traction control systems is how they work with engines, where they interact with the ECU to reduce engine torque to curb wheelslip when one drives like a hoon or when conditions are really adverse. Another related but perhaps lesser known function is Engine Drag Torque Control. The engine braking effect, especially at high rpm, can cause wheelslip where the driven wheels end up too slow compared to the others. Say, if the gas is suddenly released or if aggressive, driver chosen, downshifts are not rev-matched. It's the opposite of the earlier TCS situation. In such situations, EDTC partially opens the throttle to more smoothly ease in the engine braking effect. It's sort of corrective in this sense and it does theoretically raise the idle rpm when active as the throttle opening is not caused by the driver's input. With more aggressive throttle programming and synchronisation with the transmission computer, the core EDTC function has evolved to the fast and smooth rev-matched downshifts seen IRL in the various types of automatic transmissions. Similar to how the ETS/ABD/eDiff functions seen in 0.19 have evolved to full-on cornering torque vectoring by braking. Currently in Beam 0.19, when one downshifts anything with a dual clutch, the gas pedal can be seen actuating, which definitely isn't the case IRL. The reason is that the DCTs share the rev-matching logic with the assisted manual transmissions, and the automatics totally lack it. One could therefore reason that the core ability to dynamically adjust throttle or idle in a 'hidden' manner via the engine simulation, instead of only through the game's assists, should be added as it's a prerequisite for adding realistic auto rev-matching. Another possible end result of 'hidden' throttle manipulation is the ability to simulate rev-hang, for emissions.
I think this could be implemented relatively quickly but most beamNG cars do not last long enough to come out of the warmup phase.