Hm. Nope. Whatever that "materials.cdb" file is, its not a "Constant Database" file. Found information on the CDB format here: https://www.unixuser.org/~euske/doc/cdbinternals/index.html The first 8 bytes are 4-byte binary integers followed by a bunch of 4-byte offsets into the file. This file starts with "BETH" and then lots of ASCII characters. So no idea what type of file we've got here.
This might be something I'd consider for inclusion in my Starfiedl mod, in the future.
The main problem would be not having audio for responses to new options, if any new options would warrant a different response than the ones that currently exist.
Or do you just mean a bigger bank of things for the PC to say that still lead to the same responses we already have from the NPC, or even just re-wording of the existing player responses to be a little...I don't know...better?