I recently discovered that __ added to the end of specific BZII controlled model part names rendered them fully operational when exported from Truespace as DirectX models; it's not the XNA X version used by TS 7.6, but the older version included with Truespace 7.6 and labeled Truespace 6. In the past, I used to have to manually rename these parts one at a time as the X exporter tacked on extra characters rendering the game controlled parts as non-functional. This meant that unit hardpoints like weapons would not work at all. However, I finally realized that the __ meant something to the BZII engine; it ignores characters after this symbol set effectively making the engine see the original model part name, i.e., hp_gun_1 not hp_gun_-1. Now I can just export the X model from TS without any further editing, and directly convert the X model to BZII XSI version 1.5 with 3d Exploration version 1.5.5. The process saves me a ton of time and I can get models in the game for further testing.
Update: Using a TSX plugin called TrueX is a better way to export X models out of Truespace or Gamespace as it preserves the model parts name. For example: when you name say name a part like hp_gun_1 for BZII the model will export to X and the part name will remain exactly the same so that when the model is converted to XSI in 3D Exploration and saved in your BZII Addon folder the model will work correctly when BZII converts the model to a MSH model file. This is a great time saver for getting working models in to Battlezone 2 Combat Commander. Just remember to create a new ODF file for your model so you can test it out in the BZII Map Editor. Also, if you plan to modify the model again in TS remember to delete the old MSH model in your data/bindata folder and repeat the above exportation and convertion process. BZII, will create a new MSH model when you load the model in to the Map Editor for retesting. 
Then there's also John Cordell's TSX based TrueX exporter for TS 4 and TS5 object/scene exporter that preserves the BZII parts naming. Only drawback if it trianglulates the model when it exports. I prefer the default modeside X exporters as it doesn't automatically triangulate, but has an option to triangulate if you wish, in addition to several other export options.
