the pool charges you for being big. put the block on a sheet instead: post the intent, makers bid sealed, best price wins, and it settles in one transaction with the pool bypassed.
write the block on a sheet: ticker, size, side, window. no price shown, no order book, no footprint in the pool.
desks quote against the sheet inside the window. every bid stays sealed until it closes, so nobody shades off anyone else.
bids reveal, the winner is stamped, and the whole block clears atomically in a single transaction. one price for all of it.
slippage is a curve that punishes size: the bigger the clip, the worse your average fill. a sealed auction flattens that line, because makers price the whole block once instead of walking your order up the curve.