First off there is a new site command to easily create symlinks, but there is no TCL binding so just use existing methods. Deleting them is vastly simpler now since FTP clients can delete them like ordinary files. Good stuff, but doesn't affect you either
The really big change is relative symlinks. ioFTPD v6.2+ symlinks now behave exactly as their unix counterparts do in terms of resolving paths. Thus you can now use links of the form a -> b, a -> ../b, a -> ../../foo/b, etc. Previously it was necessary to prepend an extra "../" on the front so a -> b had to look like a -> ../b. This was clearly wrong when viewing a directory listing and not consistent with other ftp servers.
Most scripts seemed to use absolute paths so this change didn't affect them, but I prefer relative links in a lot of cases. Especially for things like no-sfv, bad-diz, and incomplete tags referring to files in the same directory.