Using subprojects {} from build is considered an anti-pattern. Actually, referencing any project from another is consider an anit-pattern. It forces all of the projects to be evaluated and configured even if running tasks in just one.

In ORM, e.g., we instead use common script fragments applied to subprojects as appropriate.

An even better option is local plugins to accomplish this - I have just not done this yet with ORM which is more complex.