The Github issue is closed, so I take it here:
Why are the science and production yields displayed correctly, but culture not? Are they handled differently by the program?
Yes, they're displayed differently. But I think I fixed this, no? If not, make a new post detailing what I missed.
Long story short, all yields use roughly the same logic except for culture and faith, which operate on their own weird isolated set of rules. Whoward fixed a lot of this in the DLL last year with his unholy unified yields effort, but LUA was not affected by this quite so cleanly, meaning that most LUA functions still relied on the old spaghetti model.
G