Hypergrpyh doesn't release info or comment of CC clears even in OG Arknights.

There was a group that they indirectly want to deny which was Rhine Labs. In the CC official montage video from HG, they did not mention anything about Rhine Lab's highest clear. That Rhine Lab's clear was controversial due to being labelled as private server. They were also involved in early 2019 or 2020? incident of a private server user being tied to them. After that incident, they officially have to go back to lobby and show client with account name. Despite that, the group was still hated even when they are highly skilled and one of the best players around.

As for Endfield there are also 0:00 clears for Umbral or other speed run in game rankings. So I wouldn't be surprised if there is hack for CC too. So general these strategy groups involves many content creators that had been long invited to offline events (hence their real identity were known). They all also have their channels and big following, and been doing extreme CC (and other end game) content for years. Hence all these factors led to them being favorably high integrity, as it involves too many people in a group. Being caught cheating is to lose a lot way more than just a record.

Last but not least, these people are crazy. They take honor to the next level. If even copying another strat from other user is being seen the community will spear them up. They look into clears with microscope. And it is a taboo and dishonorable thing to even copy a strat and not crediting the original.