Filter issues MUST NOT be reported here. Read first: https://github.com/gorhill/uBlock/blob/master/CONTRIBUTING.md

Describe the issue

The current "Import and Append" button does not clear the existing whitelist if a user is maintaining a whitelist offline (Git repo, etc). A manual step is required to clear the existing list before importing its replacement.

One or more speci

This addon supports "Acceptable Ads" and is a fork of uBlock Origin which doesn't. It seems that their manifesto was carried over from their git repository when forking:
https://github.com/uBlock-LLC/uBlock/blob/90ac9d52b987aafecd2cf44a67f8a2eadd712d20/MANIFESTO.md

I have a proposal for fixing it, let me know what you think

This is uBlock's manifesto

1. The **user doesn't de