Can you elaborate more? When you say "checks and balances" do you mean explicit legal mechanisms or implicit mechanisms like Tiebout-style foot voting? For the latter areas with "almost zero oversight" seem advantages. Also, can you give an example of these low-oversight places and how it manifests? I'm thankful even for some pointers in what to search for.
One example is the effective prohibition on spraying pesticides by air, including drone. Drones allow lower pesticide use than current, legal practices
Oh, so "parts of the EU" wasn't about geographic areas but policy areas? But this sounds like more regulation, not checks and balances either. Are you replying to the right comment?
It’s unlikely because smaller member states wouldn’t want that as they’d be outvoted by bigger members and thus forced to implement laws that might not even make sense in those (smaller) countries.