If you're not already aware, there's a service at https://rss.ponder.cat that also does this. The post at https://lemmy.world/post/20508996 shows how you can use the bot to send articles from RSS feeds to a particular community.
I'm guessing that anybody using this tool would need to be careful with it, since a new post every time a feed updates could get spammy. A separate issue is that posts that are just links to external sites, with no summary, don't always engage people much (we're all reluctant to click, because of how broken the modern web is).
Sorry to be negative - it does look like a cool project.