Would it be possible to use interwiki links in the File(import|export) summaries instead of full URLs? This would allow easier navigation between the deletion log and the destination repository where the file now lives.

$1 in both MediaWiki:Fileimporter-cleanup-summary and MediaWiki:Fileimporter-delete-summary is a URL, so it can't be customised.

In addition, T260109: When importing file from X to Y and deleting X, the deletion log summary on X is drawn from Y's wiki instead of from X should be addressed so individual wikis could customise the delete message instead of using the commons' one.

Thanks.