Final depth of O:CH T3 does not give the correct rarities.
In fact, it gives lower-grade rarities compared to the 2 depths prior to that final depth.

I reported this ingame right when the change happened [Feb 2014?], but nothing has done to fix it.
I haven't double-checked the equivalent depth, but the final depth appears to be around D24. It makes no sense to have the final 12 boxes from OCH be less valuable than the boxes on the depth prior. It should be around D28 [the same as FSC's final box room].