Z-Image-Turbo-unsloth-bnb-4bit (and any pre-quantized bnb/fp8/nf4/gptq/awq
checkpoint, or a runtime-quantized model) dequantizes to a HALF compute dtype
and its transformer uses FlashAttention, which only supports fp16/bf16. The
per-model image loader defaults precision to f32, so such a model loaded in
float32 and crashed with "FlashAttention only support fp16 and bf16 data type"
(image/character generation → 400/500), besides wasting VRAM.

When precision is left at the f32 default AND the model is quantized (name
contains bnb/4bit/8bit/fp8/nf4/gptq/awq, or config sets load_in_4bit/8bit/
component_quantization), load in bf16 instead. Non-quantized models keep the f32
default. --no-ram already forced fp16, so it's unaffected.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RdMufYvtTbtGDWsiZVoXce