Please explain Why....?
I'm not aware of ANY negative aspects of raised the idle with UD crank pulley. FYI, tuners do it all the time with engines that have a larger aftermarket cam.

 

Sometimes the battery voltage will drop on mine when it is idling.. not too far to worry about though.

 

Try blipping the throttle slightly above 1000 rpm when you start it up. Some alternators won't turn on until they reach a minimum rpm. So the battery will still be the only power source until that happens. If that not the case with your car you could possible benefit from raising the engine idle rpm, depending of course on you current engine idle rpm.

 

I got the SLP pulley and have no issues at all. Also gained 9rwhp