In the stock game the part variants feature is usually used to set a skin on the part. I.e. all the other physical properties stay the same. However, this feature allows changing many other properties, like the attachment nodes and the models. And in this case KIS becomes vulnerable, since it cannot preserve the variant, chosen in the editor, in its containers. It always stores the "default" variant, which can be anything (either usable or not).

Major issues, derived from the statement above:

1. It's not possible to set a variant when adding a part into the container. A random state will be saved into the container.
2. The affected part, pulled out of the container, may have an unpredicted behavior in the flight scene.

Ref: d6d2ade
Ref: 5079372

The only left-off is #296.