No direct response to your question in the post as I have never seen anything like that before.
All he's done is shift up the same stubby early ST824 chute 15 inches. The chute has the
same back angle as before the extension. The angle is sharp and if he took the picture with the chute
turned a few inches to the right it would show the full sharp angle which would be more than shown.
No real change except putting the chute up a few inches. Minus for going against gravity for 15 inches
and plus for being 15 inches higher. With the same back angle as the original the result would probably
be a hardly noticable improvement that was not worth the effort.
A later ST824 would have been a better choice or some other chute from another machine that was taller.
Not that taller like his makes a difference. Taller to have a more gradual back angle.