At least, it's their policy:

Just so you and everyone else is aware, we have the policy of not monitoring CJ feedback on any external (to Google) forum. If you or someone you know has feedback that can/should be actioned, please ask them to either use this list or contact us privately at [email protected]. They can also use our social channels, but it's a less efficient form of communication for system-type feedback.

So, it you have a technical problem during the upcoming Qualification Round, rather than posting it here on Codeforces, email it to [email protected]. Or do both.