I've just caught a shiny in the safari zone, but when I finished
exploring the chain disappeared so I can't see in which chain
number I succeeded (somewhere between 120 and 130 I guess).
I agree with the broken chain as it's a way to avoid a flood of
shiny vivillons onsite, but it would be useful for shiny hunters a
way to see when did they get their shinies (same as happens with
the common pokeradar)