Have been doing some additional investigation today, and I have learnt a great deal. I would like if someone could confirm the following conclusion:
The IA exporter only exports objects that have at least one keyframe. Objects controlled by parenting will simply inherit animation of their top node. Objects animated by constraints such as LookAt and such, will be skipped by the exporter unless a keyframe is present.So. Further results of the investigation. Per Mike Adam's tutorial, I've experimented with using position and orientation constraints to move bits and pieces along with their respective bones. This has for now been applied to the RH valve gear, the LH valve gear is simply animated using parenting to bones. All works fine in 3DS Max.
Here's the hierarchy:
Objects underlined in red are bones, that have been converted to edit mesh. Underlined in green are geometries. Green boxes are helpers, such as points and IK solvers. Underlined in yellow are objects that the IA exporter failes to recognise the existance of. All have one keyframe applied. See the export report below.
So, we see that some geometry is being exported. However, all bits underlined in yellow in the schematic view are missing, leading me to conclude that these aren't being exported (i.e. TS will think 'lol those aren't animated).
Well, it's more of a report than a question, and I'd like to really apologise for coming over rather frustrated with content creation.