Function ffn_act_keep 

pub fn ffn_act_keep(
    model: &Arc<CmfModel>,
    w1: usize,
    w3: usize,
    w2: usize,
    xs: &[f32],
    b: usize,
    hidden: usize,
    inter: usize,
    act: GraphAct,
    out: &mut [f32],
) -> bool

The LLM prefill’s dense FFN for separate gate/up/down weights in any codec with a device GEMM (int8, q4tp, or a mix of them): the panels stay on the card between the projections. wgpu only; other backends decline and the caller keeps its per-GEMM path.