I've read about this thing and it's $47 shipped in the US. There are a few Vstar 1300 folks I read about that got it and liked it. The problem it solved was that for the Vstar 1300, there's a bit of a surge at low speed. This allowed more friction zone to manage the surge.
I don't know if it will help your stalling issue but with more friction zone, it surely cannot hurt it.
I'm mostly interested in this for reducing clutching fatigue. After practicing Ride Like a Pro techniques for say 20 minutes, my left hand is quite sore and I often have to stop and shake it out before continuing. It's just hard for me to justify the $47. If it was $37, and could ship to me next day, I'd get it.