Resign and Resume (Casual)

Were you ever playing a great tense game but it was ruined by a rare blunder? I've been on both sides of that equation, and would love a resign/takeback/casual option to resume a game while conceding the loss after a takeback. Thoughts?

You can request to play from the position just before the blunder.

How does one do that?

Resign, navigate to the ply you want to play on from, click on "Analysis board", then Menu, then "Continue from here", then "Play with a friend", then choose your time control, choose your side, type in your opponent's username.

It's quicker than it seems.

@DoTheMath is correct.