Function max_requests 

pub fn max_requests(
    n: u64,
    mode: &RankMode,
    bias: &Bias,
) -> Result<u64, BoundError>

Declared request bound (039, 3.5.4, 3.6.3, 3.7.5), not actual requests. In particular listwise’s declared bound is orders even for a zero pool bound; request planning must suppress requests for an empty actual pool.