Sounds like a pretty interesting and unusual use case! Do you by any chance have a working sample you can share, ideally a Playground? There are a couple things that seem a little confusing to me which might be cleared up if I could see them in action.
If you don’t have a working sample, I think the main two points of uncertainty for me are as follows:
I’ve almost never seen anyone invert a projection matrix before. In fact, my understanding is that canonical projection matrices cannot be generally inverted. Can you dive a little deeper into the reasoning behind what this is doing and why you need to go about it this way?
Typically when values need to be recomputed, I would not expect them to be frozen as, without that, most of them will recompute themselves. Can you help me understand what all the freezing is doing? If, for example, you could achieve the effect you’re going for via a more conventional usage of the variables (setting the position and allowing values to auto-recompute on render), would that be an option?
It is the same issue, main problem is we can’t make a playground because the 3D context come from mapbox. To resolve the issue we need to explore the mapbox API and find a better way to reconstruct a babylon camera from the mapbox camera attributes.