So...please do not release non-beta aircraft and scenery based on beta builds like 930.
Here's an example: the current spec for attached objects is that the draw order is based first on lighting mode, then on the order listed in Plane-Maker.
It turns out that if we do that, polygon offset can't be used in a number of weird cases. So the rules will have to change. I'm not sure what they will change to, but the decision will be finalized when 930 is finalized.