skew or stretch are not baked propertly

[pKrime]

angarilow (T57536):

Specifically, animations for rigs that use non-uniform scaling on parented bone chains (i.e. all common stretchy rig setups with Stretch To) cannot be correctly baked, and thus often cannot be correctly exported. The only workarounds are to either not use non-uniform scaling (no fancy stretchy rigs), or unparent all bones.