Qwen3.5 4B

User asks how to enforce a closed JSON schema (constrained decoding) for Qwen3.5-4B running on a Snapdragon X Plus X1P64100 NPU with 15.6 GB RAM via GenieX 0.9.3 (geniex serve --compute npu, GGUF Q4_0, ggml-hexagon backend). They report roughly 13 tok/s on the 4B model and want streaming, constraint only after the thinking block, and no Python or compiler on the end user's PC. No benchmark table is given; the questions cover whether geniex serve honours json_schema or grammar, whether a llama.cpp Hexagon build supports --grammar/--json-schema on Windows ARM64, whether Genie SDK or ONNX Runtime GenAI expose a constraint, and possible logit-bias or logprob workarounds.