polygons have never had support for individual heights – this has been a highly requested feature, but since 2.2 was focused mostly on bug fixes, memory, and speed it didn’t make it in.
I’m not aware currently of any oddities on line heights – could you explain further?
I only have it occur when I have a line with no vertex heights set, and then set a custom height on a vertex NOT at the end of the line. Doing so causes an odd line height change at unrelated vertices.
This is definitely a bug, and I’ll put it in the database.
The workaround is to have >1 vertices set on a line; this seems to fix the error