Manifest V3 Migration: The Gotchas Nobody Warned Me About

When Google announced the Manifest V3 deadline, the developer community had a lot to say — most of it negative. The service worker model was rightly criticized as a regression for ad blockers and complex extensions. I've now migrated 18 extensions from MV2 to MV3, or built them MV3-native from the start. The commonly documented issues (no persistent background pages, limited webRequest) are real. But there's a longer list of subtler problems I hit that weren't well-documented. Here's what actual