Not my project, but another approach recently published used Depth Anywhere to create a virtual depthmap for a given 360º equirectangular image and then apply to point cloud and render using three.js / A-Frame.
Appears to be similar capability as OP for creating scene depth from 2D, but using point cloud instead of gaussian splatting for rendering so looks more pixelated:
https://github.com/akbartus/360-Depth-in-WebXR
Also unlike the World Lab example you have the ability to go further outside the bounds of the point cloud to inspect the deficiencies of the approach. It's getting there but still needs work.
Yes and this is a great example of how open A-Frame is compared to OP example. You can inspect every part of the experience from the code to the actual runtime inspector to see how Akbartus achieved the effect -- and then help to make it even better! :)
I do think there is the possibility to use something like this eventually to do all the processing in the browser for Depth Anywhere + Splat reconstruction to fill in the holes of the current point cloud approach: https://github.com/ArthurBrussee/brush
Appears to be similar capability as OP for creating scene depth from 2D, but using point cloud instead of gaussian splatting for rendering so looks more pixelated: https://github.com/akbartus/360-Depth-in-WebXR
Also unlike the World Lab example you have the ability to go further outside the bounds of the point cloud to inspect the deficiencies of the approach. It's getting there but still needs work.