WPT details: See https://github.com/gpuweb/cts/pull/3679 WebGPU/WGSL have a conformance test suite (https://github.com/gpuweb/cts) that is regularly pulled into Chromium and part of the testing of Dawn/Tint in Chromium.
Functionality added to the WebGPU spec after its first shipment in a browser. Adds the optional GPU feature "dual-source-blending" that enables combining two fragment shader outputs into a single framebuffer. This technique is particularly useful for applications that require complex blending operations, such as those based on Porter-Duff blend modes. By replacing subsequent render passes with a single render pass, dual source blending can enhance performance and flexibility
The “dual-source-blending” GPU feature adds additional blend factors and the WGSL @blend_src attribute to allow a fragment shader to blend two color outputs into a single output buffer.