When reading papers, what's the most convenient way to check a citation without disrupting the reading process?

If you're using Adobe Acrobat Reader (which I suspect you are), you can press alt + left to jump back to where you were before clicking the link. I find it amazingly useful.

If using Preview on MacOS, you can use Command + [ to go back.

In a web browser, you can right-click and select "Open link in new tab" or whatever the specific option is for your browser. Then you can click through the tabs rather than scroll through the article.