Underlying APIs allow the source and destination textures to have different formats. We need to investigate the full matrix of allowed format pairs (and aspects) for copies.

• It would be convenient to be able to copyTextureToTexture between the srgb and non-srgb versions of a format (e.g. rgba8unorm <-> rgba8unorm-srgb). Regardless of whether we get view reinterpretation in Proposal: Add a usage bit to allow creating a view with different format when creating a texture #168, this is helpful. (Copies operate on textures, not texture views.)
• Contradictions in the validation rules of copyTextureToTexture() with depth stencil formats #1464 highlights spec issues with depth/stencil format copies that would get resolved by this.