Okay, things look kinda bad when both upward and downward expansion are involved. (example post, and the one above)
This is an issue currently as well, though.
I think that upward expansion needs to be fixed in a sense that it looks like downward does currently, i.e. it should be inserted in a way that makes:
- The wide line appear above the in-reply-to and post rows
- The narrow line appear between the in-reply-to and post rows
- No double lines anywhere.
Fixing the scroll issue then becomes an afterthought.