Yes, it is compressed, basically an LZSS variant. I have a working decompressor for Star Ocean, but it shouldn't be too difficult to write the complementing compressor, though I doubt the thread creater is technically versed enough. The game saves for each of its compressed blocks the compression type into the header of the block, so you could also just use 'uncompressed', but it's hard to believe a full script would fit in then.
PS: As far as I know DeJap also added Huffman coding to the game.