The design shifts to optimize for workloads where short actions return long observations that require frequent prefilling of a growing context. To reduce overhead, HySParse2 utilizes 'KV Bridging' to build cross-decoder K/V from self-decoder hidden states and 'KV Reuse' for sparse layers. Additional changes include moving to token-level selection and implementing a forced window of recent tokens to allow local and global tokens to share a single KV cache.
