Since the latest patch (04-26-2024) the Gadgeteering On-Next-Hit buffs/debuffs - Sonic Device, Toxic Nanites and Miniaturization Drive - now all go on a shared recharge timer when only one of these abilities is activated.
Previously, these abilities could be used in succession or even be active at the same time.
This change was not documented, and hopefully is not intentional.
In-game, I'm The_Kef -- ¯\_(ツ)_/¯ "That's really it for Champs."