What action(s) are you trying to use for "Refresh Library" aspect? As the options which specifically refer to refreshing only involve metadata & will not add new files into the local library unless you're meaning the folder monitor / import folder actions?
If it's the folder monitor / import folder actions then as long as the file(s) can be seen they should be being added in unless the flac input plug-in is missing &/or preferences -> media library -> local library -> supported files type tab is not showing FLAC as an enabled option.
You've also mentioned "long album title", is that within the file metadata or as part of the actual file path? As I currently only support file paths up to 260 characters & don't really have things in place for super long file paths (though there's an attempt to get the DOS 8.3 filename as a workaround). If it's within the file metadata then I effectively don't have a limit on the string length that can be read so I could do with some clarification on what's actually involved please.
-dro