Electronic Ign. Control Unit (ECU) Heat condition

A separate feed from battery to relay post helps reduce voltage drop and starter electrical noise when cranking. I think fusible link connects at post along with most electrical loads. Having electronics "ON" when cranking may lead to early failure.

While the long battery leads may have low resistance, they have inductance too. The battery normally serves as good filter, just like a capacitor. The long leads changes that. To have any chance with electronics, best to feed power from battery terminal connection, not starter post as it exists now.