Reported in Miraheze discord. Since https://github.com/wikimedia/mediawiki-extensions-Editcount/commit/e5657bc2997f6bfbc1f35f3f019847d6639ad03c, the Editcount-before message is included in both the special page and the transcluded page.
This breaks using the special page in a template.
The editcount-before message should be moved to inside the else of this->including