[Bug]: quantized model save warning conflict

[chensuyue]

Problem Description

immediate_saving will save model during quantization, so the warning in export_to_fp.py will always be triggered, logger.warning(f"{output_dir} already exists, this may cause model conflict") which is not readable for the user.

Reproduction Steps

Quant and save any non-fake models.

Environment Information

No response

Error Logs

�[38;20m2026-05-20 10:42:09 INFO shard_writer.py L324: model has been saved to /media/jenkins/saved_models/Qwen3-30B-A3B-Instruct-2507_mxfp8_fp8attn_LLMC/Qwen3-30B-A3B-Instruct-2507-mxfp-w8g32/�[0m
�[33;1m2026-05-20 10:42:10 WARNING export_to_fp.py L311: /media/jenkins/saved_models/Qwen3-30B-A3B-Instruct-2507_mxfp8_fp8attn_LLMC/Qwen3-30B-A3B-Instruct-2507-mxfp-w8g32 already exists, this may cause model conflict�[0m

Additional Context

No response