A local build will take ~2 minutes to build. But the same build will take 15 min at least on Xcode Cloud. Can anything be done here?
Our engineering teams need to investigate this issue, as resolution may involve changes to Apple's software. Please file a bug report, include a small Xcode project and some directions that can be used to reproduce the problem, and post the FB number here once you do.
Bug Reporting: How and Why? has tips on creating your bug report.