I'm also unfamiliar with this, but if it's just expanded clay like @Kadebe suggests I cut my costs digging shale nearby. Mix with components that mitigate its tendency to align and layer itself (decomposed granite for instance) and it holds moisture and resists compaction.
I often suggest people research the old ways of indigenous tribes here to problem solve their camping issues. Research your local geology to problem solve your soil issues.
Supalite Black - Medium Grade - Bonsai Growing Media Supalite Black our lightest weight growing media 4-8mm mesh graded to produce an approximate particle size close to this range Frost proof fired clay product Made in the UK Information on how Kaizen Bonsai soil products are described, graded...
I tried that LECA stuff because it was cheap. If it was a smaller more uniform size I might have been able to justify using it but I wasn't a fan. Still have a big bag of the stuff laying around somewhere.
I've used it a few years ago. It's very much like LECA, very lightweight and very long-lasting. It's OK but I prefer Akadama/Pumice/Lava. The particle size means it's too big for small trees/pots, but it would work OK as a soil component in a big pot.
I've used it before, it needs to be mixed with other ingredients, it can't be used straight. The smaller grains are so lightweight they can sometimes float which is annoying. I think you're better off sticking with the big 3, PAL or "Boon" mix.
We use these specifically for orchids because they retain water well and they make it so we don't have to water as often. I hadn't considered using them for bonsai and don't plan on it but they work well for orchids. An expensive option though but we have over 150 orchids. We only use these on a few varieties.