The memory card should have no config.txt at all. If it does, delete it. As I said, your tai config needs to be I'm ur0:tai/. Any other config can be deleted. And the 2GB space is internal storage, the OLED Vita's did have internal storage, just not mounted for use as a memory card. The Vita 2000s use the same space, just split into 2 ~1GB partitions.