This is how that chariot looks in 3ds Max 2018 (Student Edition, Free), I just extracted it now:
Is there still stuff missing that you know should be there?
(original size:
https://i.imgur.com/4fseJO7.jpg)
If there are known attachment points missing, I would very much like to have the name of those, so I can check if there are errors in the exporting code, and in that case, fix it
The WH2 exporter code is quite new, so it is certainly possible. Also, there are some additional attachment points in the RMV2 model itself (as opposed to on/in the skeleton), I can take a look there?