Function check_e4m3_grouped 

pub fn check_e4m3_grouped(
    gpu: &dyn GpuBackend,
    kernel: KernelHandle,
    a: DevicePtr,
    expert_offsets: DevicePtr,
    sorted_token_ids: DevicePtr,
    num_experts: u32,
    k: u32,
    stream: u64,
) -> Result<()>

2026-09-30: The grouped (pointer-table) MoE form of check_e4m3_activation_range. The kernel reads A row sorted_token_ids[p], or row p when sorted_token_ids is null, for every position p in expert_offsets[e]..expert_offsets[e + 1], e < num_experts; only those rows are checked, each k BF16 values wide. A no-op for a kernel that keeps A in BF16, in release builds, and under graph capture.