If the intention might be to import these files somewhere else, how do you avoid all characters coming in with full inf and a full set of purple/PvP IOs that have been transferred from toon to toon before exporting ?
The only way a toon could be imported with such OPed gear is if Sentinel+ files were basically being imported to another version of CoH, identical right down to the systems. Nobody here is running a private server of CoH, and Plan Z/Titan City will be an entirely new game, precluding any attempt at a direct import. I'd imagine that characters ported into Plan Z, once it's up, will basically be little more than a name, a concept, a general set of powers, one or more costumes,
maybe your badges if you're lucky.
Can you happily edit these files ? (if for example you lost a name doing a server transfer or thought you shouldn't have been genericed and want to change the name back).
The files are simply XML, so they're editable. However, there may be checks in place, once a successor is ready to import them, to prevent the use of edited files.
If you want to change a character, copy it over to Beta and use a (free in the Paragon Market) Character Rename Token to change the name. Then re-export the character with Sentinel+ for Beta.