I shared the concerns of this author. I wrote a free tool to use simple heuristics to predict if text was generated by ai or not - https://isthistextai.com/
To be honest, the heuristics here are kind of bad... The first two paragraphs from Wikipedia page for Viterbi algorithm return as AI generated, while several samples from TinyStories, a GPT-4 generated dataset of children stories for training small LMs, get flagged as certainly human. Maybe the weighing can get some work, or you can just switch to a proper classifier.
Thanks for your feedback! I built it as a hobby project to explore this space and learn a bit more so I’ll keep learning!