I found another solution called SliderCaptcha. Basically the way this works is that upon saving/creating an account/etc., a popup with an image and a puzzle piece appears on screen. Using the slider, the puzzle piece must be moved in the correct place. Similar to this mockup, except that the CAPTCHA can also be done in English:
The code is Apache/MIT licensed so it should not be too difficult to implement on ConfirmEdit.
Something similar is already used on TikTok and Genshin Impact and appears to be somewhat effective at stopping bots in their tracks. We can do the same, but with images from the Wikimedia Commons (probably images of places or tech or cookies or something like that).