If you are using the XcodeProj-based integration, then we’d need to add support for this, indeed. Because Tuist enables you to cache external dependencies, you can build a particular version of Swift syntax once and then reuse that across all your projects even without this feature, so we don’t feel there’s such a strong need to add support for this. However, it’d still be a nice addition and we’d be happy to help anyone who’d like to contribute this.
We would most likely need to re-implement a version of the PrebuiltManager from SwiftPM to download the binaries and then replace the source variant with the prebuilt variant in the PackageInfoMapper (or later on in its own repo).
Feel free to create an issue for this one on GitHub 