Some wikis use VisualEditorAllowExternalLinkPaste to prevent external links from being pasted from text processors.

Some experienced users use a text processor to prepare their edits offline or in a quieter environment. They can't paste all their work on wiki, as all external links (sources) would be removed.

Possible solutions (based on this conversation):

• add a threshold to the configuration so that users with more that $value edits would not block pasting external links
• add a preference to allow users to unlock external links paste