As some of you may know, The V-Easy is sold as a YES GOLF product who work in conjunction with the Harold Swash putting school. Their head instructor is Phil Kenyon who teaches Lee.
Phil has seen the V-Easy and was impressed but obviously wont use it with everyone.
If Lee was to use it, he'd need to change his style as he putts 'elbows out', similar to Rory.
Luke and other good putters tend to putt with the elbows tucked in ...ala the V-Easy.
Time will tell
I've never been a fan of the elbows out technique. I just think it adds another hinge that can alter the path of the swing.
I prefer to see the arms hanging naturally so not locked out but not bent either