Will be interested to hear if you've tried it out and what may have been missing?
The only things we don't block at the moment is some non-English content and Adult sites. With a small team these haven't been the primary focus for the time being. Other than those though we should stop pretty much everything else.
We recently moved to a paid app model with a 30-day free trial available (from a freemium app model).
Understand that this is not as appealing as a free-forever product. We found that we had hundreds of thousands of free users and not enough paid users. After developing the app for many years under this model, we had to make some changes so that we could continue to fund the ongoing app development and updates.
The notification prompt can also be declined in the alert that appears; though we could make this more obvious with a clear 'Skip' button.