Yep, thanks, I had already found something to this effect in Alerts for new RSS feed content - #2 by BLUEFROG, but it said:
which confused me – what are those „other options“? Why won’t notifications work consistently? So I figured a simple option to switch on this behavior would be a nice alternative. But of course I’ll be fine if this smart rule does the job. (News appear rarely in the feeds I’ve configured, so I’ll have to wait for some time to test it.)
Anyway, thanks! 