I ran some tests and can confirm that with Xcode 26, xcodebuild now works just as fast as Xcode 16 with the workaround. This is true both when rebuilding the app without any changes and when performing incremental builds after making changes. I also noticed that Xcode 26 no longer calls the slow developerservices2.apple.com. Instead, it uses https://ocsp2.apple.com, which is much faster.