We've got active differentials, CVTs, DCTs, LSDs, but the question remains: is there anything BeamNG's Powertrain can't simulate?
Yes. Power train devices can only take one input each. This prevents dual engines feeding same drivetrain, most notably this is how most hybrids like the Prius work. EDIT: Or yeah, direct drive is mentioned above and suffers the same issue I mention with hybrids
The powertrain can't simulate yodeling either, sorry. But, to be realistic, I'm not sure if it can simulate something like KERS.
While it's right that powertrain devices are limited to one input, it actually doesn't mean that hybrids can't be simulated. Things just need to be in series in the game. For most cases this is not a limiting factor at all, I see no issues with implementing the Koenigsegg direct drive btw.
Engine and motor would be two inputs to a single transmission is the issue with direct drive, unless a new motor was coded which itself can take an input I suppose