io3d-furniture: materials don't cast shadows unless explicitly overwritten by a-entity attributes

[Aadjou]

Problem:
<a-entity io3d-furniture="id:e1ac1efb-7505-449a-b493-680fcfb2f3a6" position="-0.82 -5 -0.6" rotation="0.0 180.0 0.0"></a-entity>

This object does not cast shadows, even though it has the material definition in the downloaded json:
"castRealTimeShadows": true, "receiveRealTimeShadows": false

If you overwrite the entire product with the shadow="cast:true" attribute it will cast shadows as expected.
<a-entity io3d-furniture="id:e1ac1efb-7505-449a-b493-680fcfb2f3a6" position="-0.82 -5 -0.6" shadow="cast: true" rotation="0.0 180.0 0.0"></a-entity>

object shadow attributes

• receive - toggle object receives realtime shadow (true or false, valid for entire object)
• cast - toggle object casts realtime shadow (true or false, valid for entire object)
• note: realtime shadows require at least one light source that casts shadows
• note: fallback to material attribute from data3d file if not set

This does work as intended for io3d-data3d files.