If anyone finds this interesting, I'd like to plug my post analyzing a similar technique, but generalized for perspective pixel art: https://tesseractc.at/shadowglass
As a retro game dev and pixel artist, this is a lot more more preferable than the constant shimmering of other recent techniques such as Texel Splatting (https://dylanebert.com/texel-splatting). Love how stable it is, reminds me of billboarding but is clearly 3D.
Edit: Ah, I didn't finish reading the blogpost - didn't realise splatting was based on yours. I actually like your variant a bit better, but perhaps that's just due to the choice of textures/models.