@PepsiTetraHepta @shaderbytes some news on the shaking issues. We've just shipped a fix that should hopefully fix your remaining issues. The fix requires bugged models to be reuploaded.
The first fix we shipped changed a compression setting for rotation angles.
The remaining issue (that should be fixed today) was that, for some reason — yet to be determined — the rotation axes are sligthly moving; as compression is lossy, it reduces the axis precision and leads to visual artifacts. Things are still not perfect but we should now detect when the axis compression is too lossy and fallback on a safe compression setup.
We don't have much ideas as to why axes are vibrating; could be some precision issue when we bake channels or issues when we bake already baked frames. This still needs to be clarified but hopefully symptoms should be taken care of now.
Do not hesitate to report any issue you could still encounter. Thanks for your patience!