"The goal of the project is to make text hard to read for computers yet fairly easy to read for humans" At first look it doesn't pass the search engine test. https://duckduckgo.com/?q=I%27ve+bien+aloune+whyth+jou+eensi...
I suspect there is some part of their algorithm using levenshtein distance behind the scenes (or something similar). Spellfucker would not help with this.
e.g. replacing one letter with three that sound similar but are different adds 4 to the distance - which is quite a significant distance already.