We have a number of custom localized strings that are used via the dita.xsl.strings extension. They are custom in the sense that they do not have corresponding @name values in the localization resources of the com.oxygenxml.webhelp.responsive plugin.
The createLocalizationFiles template seems to work so that it uses only the extension strings that have a @name value that matches an existing string in the com.oxygenxml.webhelp.responsive localization resources. Why is that? Doesn't this go against the idea of the DITA localization support of adding your own localized texts in addition to overwriting existing ones or adding new languages for generated texts? Now we have to modify the createLocalizationFiles template so that it merges all the strings fetched via the dita.xsl.strings extension with the localized strings of the webhelp responsive plugin.