Quick Cosmere ? Relating to Allomancy/Feruchemy

How was Wax able to use his steel sight to detect the feruchemical coin Hoid flipped to him in BoM? I didn’t think metal minds would emit blue lines thus being undetectable by steel/iron. I ask bc it lead me to a black hole of theoretical allomancy and feruchemy lol.

If this isn’t an oversight, is it related to Identity (or lack there of) bc that was what made that metal mind special? After all, it allows Wax to tap it and he experience’s Hoid’s memory although it’s not his metal mind. This implies it is similar to the medallions lacking identity thus allowing anyone to use them.

However, when I try to explain this, or find the connection, I get lost. Can some please help me out? Or tell me it’s a reach lol.

First things first, I feel my assumption regarding allomancy not detecting metal minds is correct but I cannot find supporting text. I hope I’m not using this much time on a bad assumption. However, I’m positive Wax sees the coin with steel sight and we know it’s a metal mind.

I believe Vin finds she cannot burn Sazed’s metal mind bc his Identity is put into a metal mind when it’s being filled. This seems true for all feruchemists hence their inability share metal minds. I assume this means each Feruchemical power has Identity inherently, as opposed to Aluminum being part of every metal mind. Yet we do know Aluminum can’t be detected by steel sight so maybe it’s that all metal minds contained aluminum. And per the Ars Arcanum in BoM, Identity is stored in Aluminum which is why I said every metal mind would require Aluminum unless identity is inherent to the Feruchemical Power. However, I still don’t think aluminum is in every metal mind bc Sazed uses a lock in HoA while captured by the Kandra.

Could it simply be that this metal mind lacks aluminum and identity as a result?

I feel like I’ve rambled enough and you might follow some of my thoughts, so what do you think? Am I on to something with Identity affecting steel sight, or am I simply on something and keep making poor logical conclusions? Lol