Litium ion batteries come from this project:
Flynano
They changed to more powerful batteries and those were leftovers...
Removing EGR system helps to lower pumping losses in full throttle mode. So when I am doing P&G driving I will get best efficiency. In a TDi there are this kind of system on the intake:
That aint designed properly for good flow. I might design my own EGR system that is not blogging the intake when being open like that system does. IMO that is just bad engineering on VW side.
That is true that EGR warms up the engine faster and lowers NOx fumes in part throttle. You can also lower NOx by installing a water injection. Water injection also increases power if you inject metanol (windscreen washing fluid) or something else that is flammable. When you install water injection you don`t need intercooler anymore which also restricts air flow.
I will install water injection and will make my pressure pipes from copper to transfer heat.
Engine you can make warm faster by making that grill block and insulating the engine. At the moment it takes about 20-30 km of driving to get my engine to 90 celsius. But if you are driving with P&G mode your fuel consumption is still 0.5 liters at gliding in neutral.