### What this PR does / why we need it? Fix TTFT degradation on Deepseek-V3.1-W4A8. Revert change of `balance_flag` in https://github.com/vllm-project/vllm-ascend/pull/7611. ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? - vLLM version: v0.18.0 Signed-off-by: Wangbingjie <wangbj1207@126.com>