Docs do not mention what it actually does and there are no examples how to use it:

https://github.com/puppeteer/puppeteer/blob/main/docs/api/puppeteer.locator.setwaitforstableboundingbox.md

From the name of the method my understaning is, I can somehow use it, to wait for element to have fixed dimensions. But there is no promise to await or no time paramater how often to check if element has stable bounding box.

There is also similar method for locator setWaitForEnabled also without explanation or examples.