@grischa Yes, you are right to assume that help files are somewhat old and not very well maintained. It is a task that few people enjoy doing, and in such a small project as Friendica, it is hard to find consistent help in this regard.

I try to update the documentation of features I'm working on, but I don't always think about it. More to the point, the rendertime addon should work, I don't think the documentation is wrong about mentioning this add-on, it's more likely that we introduced a regression somewhere.