Is there a way to have multiple line headers? Or is there a way to show headers overlapping multiple columns without the use of arrays or maptypes?
Are you talking about property names when you say headers? I don’t believe you can have a property name that has multiple lines.
If this is a hard requirement and you are technical enough to do so, you can create a slate app or a deployed app via the osdk. From there, you can have full flexibility over what your content looks like, including injecting new line characters into property names.
Let me know if I have misunderstood the question.