[fpfdafag] crowded castling

chess variant: permit castling queenside even if the square on the b file is occupied (probably by a knight).  the rook magically teleports through it.

the goal is to make queenside castling less difficult, so more common.  in this variant, one only needs to clear the queen and queen's bishop, the same number of pieces as kingside castling.  this may result in more instances of opposite side castling, which in turn may result in more decisive games, less draws, because both players can launch pawn storms against the opposing king.

similar idea: switching the directions of castling for black (future post hwaurzqi).

extend this idea to chess960.  only the destination squares for castling (in either direction) need to be empty.  both the king and rook can teleport through pieces (and each other).

perhaps teleport only though own pieces; an enemy piece on the home rank can thwart castling.

yet another possible variant: you can castle through your own obstructing pieces, but they get obliterated, as if captured by the opponent.  do such castling only in desperate circumstances.