General CI tools: fastlane + jenkins; To control Xcode GUI IDE with script codes: AppleScript; Auto create *.xcodeproj: xcodegen. You can freely combine these tools.

I made a Proj to summarize the solution: Packaged with Xcode 14.3. Unrealistic. Apple required Xcode 15 now, News. Move all image from assets to bundle. Unrealistic. Change: Assets - Image Set - Compression - Lossy, Basic. Works. But the problem is that there are so many pictures that you don't know which ones are actually render wrong. Change: Assets - Assets Catalog - Compression - Lossy, Basic. Unavailable. Other image will render incorrectly. Check image bit, if image is 4 bit or another, convert to 8 bit. Works. But the problem is some 8 bit image also have wrong render. Convert all images to 8 bit use PIL. I choose this as the final solution. Question: Can we write a script to scan images that may be rendering incorrectly?