I feel like people confuse physical mechanics with story mechanics. Dresden files focuses much more on story mechanics than physical ones.
Aspects represent something relevant to the story, and fate points govern how often they can come into the story. Aspects are typically only given to things that are important to the story, they are not meant to simulate a physical world.
Take for instance enchanted armor like Dresdens leather duster: it is ALWAYS bullet proof, but it can only be used in the story 3 times per session. It doesn't lose its enchantments if used 3 times, it just can only be used in a way relevant to the story 3 times per session. Likewise and enchanted blade of superlative sharpness is ALWAYS an enchanted blade, but can only effect the story x times per session.
So lets take the laser sight. Is it important to the story in the long term? Then it should probably be a character aspect (advanced arsenal or something). Is it a thing that comes up once? Declarations can handle that fine.
Yes, the laser sight is still there and doing something when it isn't being tagged, but that doesn't really have any long term effects on the story, so it is ignored except for the times that it is story relevant (i.e. tagged or evoked).
Imagine if it was a book? Every time you tag an aspect you can imagine it is a point being dwelled upon in a book. Can you really see "the laser sight" being constantly referenced just because it was put on the gun? It comes up a few times, but not a ton.