I have never used the kit but do have instructions for adjusting the valve to cushion the quick stop. Send me an email if you need them and I will send them to you.
I installed the coast valve in my 900 a few years back. Didn't like it and removed it. Yep, it got rid of the abrupt stop but it changed it so you didn't really know when you were going to stop. Had to use the brakes constantly.
i installed one several years ago. works great and have not experienced any problems. It is helpful when you have inexperienced drivers, however, I sure miss the engine brake.