I don't know the current availability of this package, but I want to alert you to the free STATS TEXTANALYSIS extension command, which can be installed via Extensions > Extension Hub if you don't already have it. It provides a number of facilities for working with short text data, including word and word sequence statistics, sentiment analysis and text related queries.
It isn't a replacement for STAFs, but you might find it useful. When you install it, a document entitled Analyzing Survey Text.pdf is installed in the STATS_TEXTANALYSIS subdirectory under the location where SPSS extensions are installed.