NPS Calling Station ID field limit

Hi,

we recently migrated our 2003 R2 IAS to the 2008 R2 NPS and now the calling station id field in the gui has a limit of 256 characters?!
This field in 2003 R2 IAS has no limit, what we desperately need!

Now we have to export the config to a xml file, edit this file and import it back, this is nonsense!!

Is there another tool without a limit? Or does anyone know how i can change the config in a more convenient way?