After trying out the stacked PR approached that was described by the article you linked to, I came away with the impression that it was overly complicated. And how complicated it can be could be multiplied by how many changes you need to make to underlying PRs. To top it off, GitHub does not supporting merging PRs in to target branches.

If your team has managed to follow this workflow consistently then hats off to you. But considering the options, I think it may be more reasonable to do something like pair programming for larger PRs. To me that seems like a more accessible solution that does garner the benefits of code that has been reviewed closely rather than glossed over.