MLX vision models do not currently support KV cache quantization for qwen3.5

[kay1ess]

Title

MLX vision model fails to load when KV cache quantization is enabled

Description

When trying to load a vision model with KV cache quantization enabled, the model fails to load and throws an error indicating that MLX vision models do not currently support KV cache quantization.

Currently, the application allows KV cache quantization to be configured even when loading a vision model, which leads to a runtime error during model initialization.

KV Cache Settings
KV cache quantization bits: 8
Group size strategy: Balanced
Start quantizing when ctx reaches this length: 5000
Error Message
🥲 Failed to load the model

Failed to load model

Error when loading model:
ValueError: MLX vision models do not currently support KV cache quantization