This was a toy experiment 5 years ago. It's now a recently revived double-double experiment 5 years later. (Ie, I want to use it, but dont want to start over, but want to change a few things, but ... making pasta at the office instead of in the kitchen!).
It's a combination of trying stuff out from the engine side, and from the architecture side. So there's a half-functioning bespoke ECS underpinning it now. Because it's a sandbox and not a product, not sure how much value you'll find here. At most I home to power a very goofy portfolio site with it.