Kevin, If you look at the Mistral Engines page you will see that they use a standard crank type pulley to drive a second alt. The belt runs to the outside of the bellhousing driving a standard alternator.
Bill Jepson

I admit to knowing little about them, but what of the idea to add an alternator function to the flex plate?  the rotation speed would be significantly higher at that diameter.  The PSRU seems to have plenty of space to tap into.
Kevin Lane  Portland, OR
e-mail-> n3773@comcast.net