Destabilize the Champions: Is there a good way to camp it?

[notebene.3190]

Does it appear mostly for the old champs on the east side, or does it have an equal chance of happening at the new champs on the west side? Any sort of discernible rotation?

[Khisanth.2948]

I think there are 3 champions on the west and 5(+?) on the east side so statistically speaking it should be more frequent on the east but I am not sure why that would matter.

I didn't really have to do much spawn camping for this one since it came up pretty often while chasing down every trial for the complete 20 trials achievement.