What duplicate lines are you talking about?

The debugger isn't written from scratch, just the UI. All of the underlying functionality is essentially the same, just in a more usable shell, and if you collapse the ribbon and retheme the UI to look like the 90s, you could almost squint and think it was the old WinDbg. The change is clearly very polarizing, but we're nearly at parity with what you could do in the old WinDbg UI, and we've already been able to give people features that we could have never dreamed of supporting in the old UI (not for lack of trying). The JavaScript support is just one example.

(Also, the cut-off title bar was an issue in the Fluent.Ribbon component we use, and I think it's fixed in an updated version that we're taking soon)