I'd personally rather eat prior to a workout too, and have loaded glycogen from the previous day. I like to let my body experience natural peaks and troughs which I think are important to take advantage of. I.e. let the body use stored glycogen during a workout, ramp up GLUT4, insulin sensitivity, growth factor expression, etc following the workout, and then eat big post workout.
There is logical merit to the idea of delivering nutrients to the muscle when maximal blood flow is reaching them...but from experimenting, I'm not sure that's the entire picture.
For instance, regardless of how predigested or easily absorbed something is, if most blood flow is directed away from the stomach, then it will still hinder absorption - which is something I experienced.
Also, research shows that the lactic acid buildup and general processes that the body puts forth during a workout to break down fat and glycogen (hopefully not much protein) for energy, oppose those systems that align to store nutrients and rebuild. One is actually somewhat insulin insensitive while training.
Intra workout nutrition would in theory create parasympathetic and sympathetic nervous system competition, which is what I experienced (sluggish, shitty pump, low energy - got worse with the more substrate I tried consuming intra workout).
That's not to say the method doesn't work for some. Clearly it does.