I just updated to STM 1.7.1 and Unity 2018, and I'm running into an issue with bounding box sizes. It might have something to do with the new VerticalLimitMode.
I have a text mesh that's used as the Content for a ScrollRect. I want the mesh to grow as more text is added to it, until it's eventually cropped off by a Mask component in the parent ScrollRect. Then, the player can scroll through the oversized text via the ScrollRect. Because of the ScrollRect, I can't attach a ContentSizeFitter to the text mesh — I think they conflict somehow, because Unity throws a warning and the scroll no longer works.
In the past, I think the STM bounding box automatically grew as text was appended, so all I had to do was manually resize the RectTransform to match it (via rawTopLeftBounds and rawBottomRightBounds). But no matter which VerticalLimitMode option I choose, the bounding box doesn't exceed the RectTransform's size — which means its rect can't become bigger than its parent's rect, and so it can't be scrolled through.