The BMC Ring should be a small drop chance from mobs or specific mob in the mines. Makes more sense, adds decent loot to the mines (usually there is none) and it drops for ppl who are actually gonna use it. Putting it on the Troll doesn't make much sense. Why would you need to go farm those trolls as a miner?
Here's the backstory on the ring and why it's there: https://www.shroudoftheavatar.com/forum/index.php?posts/1212525/
And so a group of adventurers killed those trolls at a later date, looted the ring and were killed by X mob while trying to use it in the mines which accounts for it dropping elsewhere. Or they can just make a mining ring and call it something else. At any rate, a mining ring obtained from the mines would be better The problem is; killing those trolls for a first ring drop based on lore purposes is fine. Having to repeatedly farm them for ring upgrades is not how a miner wants to spend his time. Also on another note, the bridge in the troll encounter is broken for pets. On the south side of the bridge, the east edge is broken. Sending pet to attack the south side troll from the center of the bridge causes pets to run all over the place