Authors were motivated by the reality that decode is HBM-bandwidth-bound; the gated MLP is the bulk of weights read per step. Threshold methods (TEAL/CATS) collapse under batching; BWAP's periodic top-k over a max-aggregated score keeps the shared batch mask stable.
The method is complementary to KV-sparsity (FFN-weight bandwidth vs KV read, context-length-independent).
Our implementation uses an adaptive mask under a captured graph (topology static = k-wide GEMM; mask change = between-replay buffer update via version-gated post_fill; prune steps replay, explore steps eager).
Preliminary Results GSM8K n=50, ±6pp: 7B dense 92% → ρ=0.5 84% (−8pp) at up to 1.40× (probe ceiling; ~10% realistic under the adaptive schedule; smaller models need lower ρ as accuracy scales with size).
Read more in the upstream issue: https://github.com/sgl-project/sglang/issues/35987