I think it does help with the delivery of blasting media. My issue is that the slope on the floor of my blaster is shallow, so the media doesn't funnel very well into the bottom hole.
But, I would say it does help. Just be prepared to make some mods to your blast cabinet.
I built a version of this design and it was a significant improvement for my HF cabinet. I have the smaller tabletop version cabinet without a stand and I had to add some feet to raise it up, but it was absolutely worth the effort.