Thanks you, exactly what i was looking for. The description of the salvage kits is a bit ambiguous but i checked the old versions of the wiki after reading your message and yes, it went from " Has a small chance of recovering upgrades from items" to "chance of salvaging upgrades"
My confusion comes from the fact i play in french , my native language, and the description hasn't changed since, talking about "obtain component upgrade" in pre and post 2018' update.
Anyway, thank you all for the multiples, and fast, answers !