Well in the meantime you could use PCS1 - there are PCS compatible hierarchy setups for COBs that you can achieve without actually opening a model in truespace. As is, PCS1 is still close to 100% reliable when it comes to model stability checking. If something crashes PCS, it would almost certainly crash or at least cause problems in FS. As such, if you're after release-level-quality POFs, that'd be your best bet.
Can you describe in more detail the kinds of stability issues you're encountering, and what processes were used to get it in-game?
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The best conversion process for each modeler will vary depending on what tools they have, but there are 4 main (fairly similar) avenues to take:
1)
Modeling in 3DS Max > exporting a POF using Styxx's POF exporter plugin. This approach unfortunately has several known issues including random crashing of 3DS, improper collision detection, faulty radius and I think some other errors that can sometimes crop up.
2)
Modeling in a non-TS app > saving as COB > PCS conversion. Because of bad/incomplete exporters, this rarely works. Typically you will lose hierarchy information or smoothing groups or all the objects will get merged into one. Blender comes pretty close here using Water's COB script, but I don't know of any other non-TS modelling programs that can save directly to COB.
3)
Modeling in a non-TS app > saving as the apps native object format (EG: 3DS) > converting to COB using 3D Exploration > PCS conversion. This method should work for programs like Sketch-Up as well as the big ones like 3DS. It will involve some experimentation as to how to correctly format it so everything will save correctly, but it can be done.
4)
Using TS as the final stepping stone in the process before PCS. This is probably the most reliable approach of all, because though I still hate it's guts, TS is the best app for saving correctly formatted COB files and aside from method #1, it's probably the only way you will be able to get any kind of smoothing groups happening.