It seems that this paragraph indicates that the system should be used only in the rear wheels, but not directly:
Page 31 of the regulations:
"The KERS must connect at any point in the rear wheel drivetrain before the differential. If connected between the differential and wheel the torque applied by the KERS to each wheel must be the same."
Considering that it should only be connected in this configuration, the possibility of connection at the front wheels is forbidden.
In respect to the engine restarting i don't know. Page 20 says:
"With the following exceptions hydraulic, pneumatic or electronic actuation is forbidden :
a) Electronic solenoids uniquely for the control of engine fluids ;
b) Components providing controlled pressure air for a pneumatic valve system ;
c) A single actuator to operate the throttle system of the engine.
d) Any components required as part of a KERS."
So, it's not clear that there is a restriction of using KERS as a method to restart the engine, as you are in one of the exception cases i think

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I forgot to say that the regulations are pretty open. Maybe we would get big surprises the next season!.

"We will have to wait and see".