Under clear coats, 2100 etc from 2013 is discussion on this. Title is Using SPI reducers in PPG dbu. Maybe this will answer your questions. Hope so. Once I started using SPI reducers everything else has just sit on the shelf.
Use the regular reducer SPI 870 or 885 and add 1OZ of ANY and ONLY clearcoat activator to a mixed quart of base and you just made your reactive reducer.
