Remove boundaries of protected_areas and postal_codes
Please remove the following 2 common types of boundaries which are clearly no admin boundaries:
1) boundary=protected_area and boundary=national_park , like https://www.openstreetmap.org/relation/1858350
2) boundary=postal_code , like https://www.openstreetmap.org/relation/13553645
There are however major updates that are in progress. We currently have a full time employee on the site, plus myself from time to time as well. There will be a couple of changes and improvements. What will help you in this case is that we'll provide multiple variants of the tree to the left. For example one of them will be boundary=administrative only.
Sadly the updates are taking a bit longer time than I had hoped for. We are making major redesigns of the code before attacking any of the bigger features. It's an investment, making the code better, before adding new stuff. I have high hopes that we'll be able to release the first updates within a month from now. Maybe even in two weeks. Depending on a lot of things it might be that we'll provide a "beta site" first.