We don't believe at this point that Chromium has backdoors. The whole codebase is open source so we as a community have to continue to keep track of it.
It's important also as some of our users are doing to use network monitors from time to time to make sure no strange requests are going out!
Omnibox input you're right are logged in many ways in the regular Chrome. In Epic, though, there is no logging. We've taken great pains to protect your privacy without sacrificing convenience. So there is no address bar history and there is browser-server interaction to get search suggestions -- instead, Epic has auto-fill for the omnibox but it's powered by a local database stored on your system.