Here's a big post I typed up before deciding to do a bunch of testing anyway:

I'm trying to make rocks for TA (yay!) but when I load them into Spring all the polygons are flipped (i.e. the outside is invisible and you can see the proper texture on the inside of the model.) I'm using s3o format and they appear correctly in Upspring v1.0 and in Lightwave 8.3 but not in the actual game. Upspring has an option to flip individual polygons and if I flip all the polygons in the model (so that it is fucked in Upspring) it appears correctly in Spring.
In case it's unclear due to messed up perspectives and reversed textures, in this picture I've gone into Upspring and flipped a few of the middle polygons to illustrate how everything is just totally reversed in Spring. You can see in the Spring shot on the left that the corresponding panel of the rock is correctly oriented while you're seeing the inside of everything else.
I imported Wolfy's peewee unit model as a feature (I replaced the rock model/texture with the peewee unit's model and texture) and it was inverted too. I then took a 3do unit that is currently in the game and saved it (using Upspring) as a s3o model and used it as a feature, and it was inverted. I took my s3o rock model and replaced the peewee model with it, and I drove around non-flipped rock-peewees for a few minutes. Note that they have the same, correct "normal body with a hole in it" as the Upspring picture on the right:

Obviously the workaround is to just flip everything in Upspring, but if this ends up being a Spring bug that gets fixed, I'll have to rerelease all the objects again, which would be shitty. So is this a problem with upspring or TA Spring or what, and is it going to fixed, and if so in which program?