No .sog support? I can't tell if .spz or .sog is likely to win out as a de facto standard - or whether both will co-exist but annoyingly I've gravitated towards .sog as it seemed technically superior and I'd be mildly inconvenienced if it became a niche format.
I don't know if the splat is exactly the same, but the playcanvas engine has no false transparency on this one: https://superspl.at/scene/7e4e9bcb that splat is actually of fairly high quality, so unless this is a materially different splat (with some of the gaussians dropped out maybe?) I'm inclined to blame the engine.
https://threejs.org/examples/?q=gau#webgpu_gaussian_splat
Gaussian splat models are fairly imperfect on average.