I too am looking at the same project.
https://www.wprssaggregator.com/exte...-feeds-bundle/
I have not tested this one.
https://wordpress.org/plugins/rss-post-importer/
I was researching this one and then it vanished. ( Like it was there a couple days ago.)
It was the free version that linked to
RSS Content Importer for Bloggers and Readers | Realtime Full Text RSS Syndication & Distribution
there is a link to a video on this page.
Feed Wordpress is on my list to test.
I am compiling a list of features.
The main issues I find is with the RSS providers.