RE: ESM Dornier DO 335
It is better to extend motor wires vs. battery wires. That being said, if you have any sizeable battery extensions, you should put the extra capacitors inline. What happens is that a voltage wave will start as the throttle is moved up and down. Generally this is only gets bad if you jockey the throttle alot, as you would in aerobatic/3d flying. Warbird pilots are generally smoother with their throttle inputs and the risk of waves is reduced. The voltage wave will take out the ESC, sometimes in a spectacular fashion.
We had a guy at the field with an electric 33% Edge that he 3d'ed quite a bit. He ended up smoking several ESCs before getting the problem sorted out. One actually caught fire in the air! Another flying buddy was running the exact same ESC with long leads in a 100amp EDF and never had a glitch. In fact, he could land and the esc was nice and cool.
I THINK??? the ICE controllers from Castle can log voltage waves/ripples in their internal log. You have to use the Castle Link to extract the data for viewing.