You speaking of that High Quality Talisman and [ I ], [ IV ] etc plates? Yes they drop from there from mobs (even when you out-level them a lot). I've been doing runs up to Yakumo killing all mobs on the way. Don't know how many I did but I've got myself pretty bored with the dorp rate. Dunno if I even got mats for 3-4 BBoE/Banner attempts. But that doesn't matter now since I'm out of Antlers,Molars,Snow Fur's etc.
Yeah, that high quality talisman, I know about the rest of the plates but did not know/remember well where I got a couple of high talismans on GC.
You are a bit wrong Crafting BBoE's is hard! I agree with that part, but u should know that red BM (black monks) dungeon also drop BBoE. This will make a difference later