No need to change the database schema or extend the code for XFMG. Image titles and descriptions can be thousands of characters, but they default to 100/300; you just adjust it to the desired limits in the Gallery Options (which can be done before an import). Same deal with media/album comments too.
Though, admittedly, there is a barrier due to the fact that there currently isn't an IP.Gallery importer...
@Chris D my bad, I haven't really looked at the schema I was just assuming. I've only looked at the gallery enough to handle the integrations I've made in various things. Should have confirmed before answering.