Due to this bug that is not really fixed:https://code.google.com/p/chromium/issu ... 261623#c86
I assume their policy for deleting settings is global.
We need a backup and restore function for all settings, filters and custom filters.
Right now we can only do a manual and cumbersome backup.
Export to file function would be a nice addition.
Note: You are competing with Adblock extension dev on answering this question. He have a 5 day head start.