A couple of problems.
We don't have a shredder/chipper and the cheaper ones look very flimsy; any worthwhile-looking robust versions are in the region of >£500! To hire one, you risk importing tree viruses such as Ash Dieback and Canker. So not sure what to do there.
Then to reach the whole root system, the mulch would need to be applied right out to the drip-line. This would make it difficult to keep the grass mown, and it would be sure to come through the mulch.
As with many such super tips, maybe it is more easily applied on a commercial scale, or for someone with only a couple of fruit trees?