Sure, it’s good and useful…

But the forced IFRAME is maxed at 500px. So viewing on a desktop, your users are forced to see a looooooong activities list and RSVP in mobile view, stashed on the left column, because they would rather you spend more money to get full web embed capabilities. If you do not want to get loaded with complaint calls, just give them the link to go to the URL instead of adding to wordpress. I refuse to believe this is an oversight.

If you do not use iframe anywhere else on your wordpress site, I advise editing your CSS to include iframe {width: 100% !important;}