Correlation or causation ?

Been digging around in some budget FBX imports to check 'relative' texture paths. Noticed their FBX versions differed.

FBX v6.1 files were mostly well-behaved, had a 'trad' hierarchy. But v7.3 ~v7.4 models had three types of hierarchy, ranging from 'trad' through 'simian puzzle' tree to 'phone pole'. Only the rare 'trad' files were well behaved.

So, is there any documentation any-where on which FBX version Poser currently expects ?? Given that may be now-legacy v6 with a 'trad' tree, may we have an updated FBX I/O in PP_12 ??