i might be old skool, but the progression I took to getting tail grabs in spins was to first learn to throw a backscratcher/iron cross and counter this by keeping your hands up. have someone film it and you'll see how close the tail gets to your hand. the next time you send this, just reach back and get that grab.
this is the pic that proved to me how easy it would be to get the grab (circa 2001). notice my knees are super bent.