Function table_chain_step_kernel 

pub fn table_chain_step_kernel<const TABLE_MASK: usize>(
    clock_reset: ClockReset,
    input: ChainStepInput,
    q: TableChainStepLaneQ<TABLE_MASK>,
) -> (ChainStepOutput, TableChainStepLaneD<TABLE_MASK>)

Stage wiring for TableChainStepLane.

Inputs and outputs as chain_step_kernel. First it wires every round the LUT way, exactly like chain_step_kernel. Then, for each table round selected by TABLE_MASK, it overrides that round: the S-box stage gets zeros, the ROMs get the (pinned) state, and mixed[r] takes the table result. Both paths have one register (S-box ROM or table ROM) followed by one mixed register, so latency stays 20.