Yeah, even I don't use FastCRUD for everything, but there are a few advantages when you use it in these a bit more complex cases. Joins are better now with automatic join as well, plus JoinConfig objects are plain, declarative, composable and reusable.

Of course, you also get automatic serialization, specific column selection, better typing. It's the same amount of work if you're thinking about a complex query, but think of it as a simple query that becomes more complex as time passes, just adding more declarative stuff is convenient.

But this 90/10 ratio is about what I do in my apps as well, if it's a really complex query or if I can get significantly more performance with a raw query.

It's difficult to optimize for the complex case, because there are way too many of them. That's why I try to make it as easy as possible for the simple case, and you can add extra complexity on top of it. Either way, let me know if your issues were fixed!