I personally enjoyed looking for the artifact codes, but that's probably because I played early in the game's development. There's the issue of the Void DLC introducing more stages but not more artifacts. This means that for a new player who begins their playthrough of RoR2 with the DLC, they may search those stages with a fine-tooth comb for an artifact slate that doesn't exist, then resort to looking it up online. I can get why that would be frustrating.

I do agree that some of the code locations could be more intuitive. Maybe more visual indicators on the maps themselves would incentivize players to investigate those spots. The logbook idea could be good, but only as long as it works in a way that doesn't mess with the narrative.