The major reason for this is Phobia - The Age. There were several bugs in the FraggleScript code that prevented this WAD from working properly.
But please keep in mind that although it seems to work now it is still made for Legacy and is not expected to run without the occasional glitch and I haven't seriously played it myself. Proceed at your own risk!

Due to this WAD I also added a new lighting mode which is closer to what Legacy is doing in GL mode. If you want to play Phobia you will probably have to use this mode because otherwise it will be way too dark in some areas.