[AndyMcConachie]

So pick a different DNS zone that isn't in the PSL but that is not an administrative boundary. They exist.

The Public Suffix list is an imperfect maintained list. You're relying on Mozilla to maintain it. You also never know if someone is selling names below their own zone. What if Mozilla decides to no longer maintain it? What if the volunteers stop maintaining it?

Maybe the PSL is a good start, but I would rather not rely on it. It's a convenience vs. security balance issue, and I'm leaning towards security.