Here's the way is works.
Anon posts without tripcode in a single bread - gets unique ID.
Same anon posts with tripcode - same ID. Scraper sites are all set up to scrape any post matching that ID within the same bread.
It doesn't matter how many times anon posts before or after the tripcode in the same bread ALL those posts will be scraped. All the scraper sites work the same way in this regard.