There were a couple of issues that we reviewed related to this. The ZeaSpatialBridge now produces more accurate bounding boxes, but they are still approximate during load. The approximate bounding boxes make loading faster, and in many cases are fine. Especially in scenes containing many thousands of small parts.
However, precise bounding boxes must be computed based on the actual geometry vertices, and the current transformations being applied. So now the engine now supports calculating these precise bounding boxes after the geometries load.
You can see the PR here: https://github.com/ZeaInc/zea-engine/pull/397
The next release will be fairly minor and contain this change. (3.7.0)
You will also need an update to the ZeaSpatialBridge which contains a couple of other fixes also relevant to you. We will make this available to you shortly.