New feature suggestion : chess without move validation

Hi community and developpers,

I have a suggestion for a new request that might be interesting for players from any level.  

Right now, when playing a move the interface show player white marks with all allowed moves visible.  The player can then click on one of theses white marks and the move is registered. 

I think I would be a great idea to have a mode where all moves are allowed for both players.  I mean, you can if you want take D2 pawn and advance it in G6 (like in real world chess).  I would add first a confirmation button (just like in slow chess interface) to avoid possible mis-clicking errors.  Then I would add a button (over the propose draw, maybe) for the opponent where it would be possible to flag an illegal move and real-world rules would apply (time penalty or a disqualification, depending on bullet or blitz, as a suggestion)

I think it would add a nice complexity and a new dimension to the game. I don't know if it have already been suggested before. Anyway, don't hesitate to add a reply !