Hex Sableye
Ive heard that dexnav chaining is kinda like how the friend safari had an increased chance. I believe its a set rate, it doesnt increase yhe longer the chain gets. I have a shiny charm, and my dexnav chain reached 400 at one point and still no shiny. i mustve had bad luck, regardless of who is correct.
Last I checked, the chance isn't set, it increases like the poke radar did.
And using DexNav I found a shiny Eevee, Snorunt, and Gible!