(Sorry for the Necro, but hopefully this should warrant a bump.)
There's a bit of an issue regarding exporting and replacing Material Entries in an SRT0 animation. Said issue is that the Keyframes from the Texture Entries don't import. There's a workaround, but it's very time consuming. This has been an issue ever since BrawlBox supported the SRT0 format.
This is my current method at the time.
1.) Open FitFighterMotionEtc.pac, and go to their Texture Animations (SRT0).
2.) Open up the SRT0 of your choice, and add a new Material Entry. Rename it to the material you want.
3.) Export the Material Entry of the original material, and replace the new Material Entry you just made. Here, you'll see the Texture Entries of the Material ported over, but not the Keyframes themselves.
4.) Export the Texture Entries from the original Material, and replace the respective Texture Entries in the new Material Entry.
5.) Rinse and repeat and save when you're done.
It's a very time consuming process, due to there being at least 100 or so SRT0 animations.
If the keyframes actually ported over, then step 4 wouldn't be needed, which would save a lot of time.
It would make things a lot easier if a way could be found to make the Texture Entry keyframes import without this workaround.