There are a couple of features that used to be rather common, a number of versions back, that I have not seen fire at all for quite a number of versions, and I wanted to check if this was intentional for these to be gone. First, Death's Hand raids, I have seen zero of for quite some time. Likewise, random discovery of codices for techs on the normal tech tree. I can see if the second was just testing the concept of codices before the Herald was implemented. If either of these were meant to be mere 'reduced in frequency', however, it might be worth checking, since, again, they stopped dead for me after certain versions.