No sync service for custom ad-filter rules across Chrome and Firefox as MV2 dies for good in June 2026

Google permanently removed all Manifest V2 support in Chrome 150/151 (June 2026), killing the last flag workarounds that kept full uBlock Origin alive on Chrome. 40 million users are now forced onto a split setup: uBlock Origin Lite on Chrome (MV3, ~70% blocking power) and full uBlock Origin on Firefox. Their custom filter lists, dynamic rules, allowlists, and blocked-domain overrides exist in two separate extension databases with no sync between them. Every custom rule has to be manually added to each browser. The existing 'migration tool' idea is a one-time move; this is an ongoing dual-browser problem. No tool exists to keep filter rules, custom lists, and per-site toggles in sync across both browsers from a single dashboard.