When running Goblin mines at levels 1-20 (essentially tier 1 levels) we get level one runes from Mimic. At 21-40, level 2, at 40-60 level 3, and from level 61 on to 97 we get level 4. How come level 4 runes are still the best you get, even as we have moved into tier 5 territory a long time ago? I would appreciate an adjustment to that.