Nice video.
Regretfully I definitely do not agree with the procedure shown.
It looks shows an incomplete root wash. So the final media is not 100% Kanuma. The result was two dissimilar medias. One in the core and one around the perimeters. The result is a fast draining media on the perimeters and a slow draining one in the core.
The Kanuma will look like it needs watering, because it will, but the core media will still be wet. Watering will wet the Kanuma and further soak the core. This is asking for root rot and likely a reason why your Hino Crimson was not doing well. No azalea would.
I’d pull the tree out. Then do a complete chopstick and root wash, removing
all the old nursery or whatever soil. You should end up with something sorta like this.
Then trim, sort out the nebari and pot in 100% Kanuma. One hint. Tuck a bit of moist Sphagnum in any areas where the roots were poor or trimmed back heavily.
Cheers
DSD sends