Customize RSS-feed: no frontmatter contents in feed [OJS 3.1.2.1]

Dear community,

I installed and set up the web feed plugin yesterday. I have chosen the following settings:

Display web feed links on all journal pages.
Display items in current published issue.

Here is a link to our Atom feed:
https://zeitschrift-suburban.de/sys/index.php/suburban/gateway/plugin/WebFeedGatewayPlugin/atom

The only thing that bothers me is that the frontmatter contents of the current issue, i.e. title page, imprint, editorial etc., are included in the feed. We have always submitted the frontmatter contents in OJS as regular contributions via the Quick Submit plugin. Is there a way to configure the feed so that these frontmatter contents are not included? Or asked differently, is there a way to configure OJS in a way to distinguish between mainmatter and frontmatter contents?

Thank you, warm regards
Michael