Wait a second. Chat control? What is that and why should we as autonomists and anti-authoritarians be interested in it at all? Chat control is officially the EU regulation for the prevention and fight against sexual abuse of children, a current project of the European Union, which is postponed for now, but could possibly be decided soon.
The hidden services bother with a robots.txt file as much as the EU crawlers.
They can just start at an Onion link collection and start crawling.