It would be convenient to check if the link is in the spam list (meta:Spam blacklist , local MediaWiki:Spam-blacklist) when adding the source.
For example, a check may be after clicking the "insert" button in the template wizard or even earlier when the type "url" in the TempalteData is set for the field.

• visual editor - cite - manual
• visual editor - cite - automatic
• wikitext-editor - editing panel - insert a template - TemplateWizard

A new user complains that a lot of time and effort is spent on editing, and a spam list message appears only when trying to save. After that, finding the problematic spots in VE and trying to remove bad links cause great difficulties for the beginner. This leads to the fact that the beginner does not save new changes.
https://ru.wikipedia.org/w/index.php?title=Википедия%3AФорум%2FПравила&type=revision&diff=108096744&oldid=108096412