Do you really run a whitelist rather than a blacklist?

That’s a weird question. That ‘yes’ seems as easy as “do you wear your seat belt? Every TIME?!?”

Is it not tedious to add hundreds of domains to one rather than a few to the other?

After about a dozen you’re kinda set. I will enable one-offs in a private window, usually for shit news sites or the very occasional referral farm, and the exceptions are all reverted when I close the tab.