I gave up on the idea of RSS on an e-reader because RSS is garbage on the vast majority of websites these days. Most of those that support it will only show you the headline and maybe the first paragraph before including a link to the full article. So you're then still opening the article in a web browser to view it--which then sends you back to the well-known "Experimental web browser on Kindle/Kobo/other e-Ink reader is crap" problem). There were only a handful of sites where I could do meaningful article reading within the RSS reader itself, and one of them (ArsTechnica) required paying a yearly membership fee for the personalized full-article RSS feed.
It's far less convenient, but just running the articles through Pocket makes for a superior reading experience (particularly on the Kobo), since Pocket will extract and display only the readable text, and avoid the nightmare that is trying to display your average webpage on an e-Ink reader browser.
It's far less convenient, but just running the articles through Pocket makes for a superior reading experience (particularly on the Kobo), since Pocket will extract and display only the readable text, and avoid the nightmare that is trying to display your average webpage on an e-Ink reader browser.