Native XML Plugin import additional galleys

OJS 3.1.2. I imported an issue with Native XML Plugin. Now I want to add HTML galleys to every article. I can add HTML galleys via web, but the problem is, that some articles contain 140 jpg images, and it is very time consuming to upload them one by one via web interface.

So I thought I could create xml file with HTML galleys in it, but is it possible that importing XML file would only add missing galleys, in my case html, css and jpg files? I.e. is it possible for Native XML Plugin to not overwrite article, to not create new article, but to import additional galleys only for existing article?

Or is there some other way to quickly add galleys with hundreds of files?

BTW, Article Component (Image, HTML Stylesheet) could be autodetected when uploading files using HTML Article Galley plugin, it would simpilfy uploading hundreds of files a lot.