macOS quick-fire questions

Can Time Machine use an APFS disk?

No. Even in Mojave, Time Machine requires its backup disk to be in Mac OS Extended format, as it relies on making directory hard links. APFS specifically doesn’t support those yet, and would likely need a new version of Time Machine to work.

Why has Safari’s content blocker stopped working?

Safari 12, included with Mojave and available for Sierra and High Sierra, disables a lot of thirdparty extensions, including many content blockers. Some, like Better Blocker (99p, better.fyi), are still supported, though. Choose Safari > Safari Extensions to view extensions that are currently available from the Mac App Store.