Integration with Redirection plugin?

And the same question regarding URLs in plain text / WYSIWGY fields created with Advanced Custom Fields?

Assuming ACF actually stores stuff in custom fields, this should work: go to Settings -> Link Checker -> Look For Links In and enable “Custom fields”. For plain text fields that just contain a URL, add the field name to the “Custom fields” text box. For WYSIWYG fields, add “html:fieldname”.

How can I get BLC to check the target URLs of redirects set up using the popular Redirection plugin?

Sorry, I don’t have an answer to that.