An asset can look correct in its source application and still fail after import into A-Frame. Treat coordinate policy as a translation problem between tools, with unit scale and up and forward axes checked on both sides.
For A-Frame, choose one authoritative unit scale, up axis, forward axis, and origin policy. Apply that convention at export time, then verify transforms and up and forward axes after a clean re-import.
Write down the unit scale, up axis, forward axis, origin, and transform-baking rule before assets enter the shared library. Apply this coordinate policy guidance to the actual A-Frame delivery path.