If anyone wants to tinker with the Babylon.js code for the 3D visualizations, I made a standalone, sandbox-like repo, which is much easier to set up:
EDIT: btw this sounds like a complaint but I didn't mean it that way. You might have really good reasons for your choice and I'm curious to hear them if you're willing to share.
I'm actually using cesium.js for the replay mode (https://cubetrek.com/replay/6638) using Google Earth data.
For the 3D mode I was evaluating both Three.js and Babylon.js, and back when I started Babylon.js seemed a bit more exciting as I could set everything up a bit faster, so it was not an objective choice. But perhaps it was the wrong decision in hindsight...
> But perhaps it was the wrong decision in hindsight
Well, it's hard to say. Babylon.js is funded by Microsoft and there's some good things that come from that. Better docs, more of a batteries included approach. I'd say it's far from a totally wrong choice anyway.