Combine or Edit Up to 8 Images With 1.5 Quality (Lower High-Tier Cost)

What GPT Image 1.5 Edit is: multi-image edit/compose with 1.5 model quality, up to 8 images, input_fidelity. Credits: low 2, medium 7, high 15 (vs 25 for Image 1 Edit high). When to use it vs GPT Image 1.5 (text-only) or GPT Image 1 Edit.