(Disclaimer: this is just my personal opinion as a developer.)
Giving operators the ability to present arbitrary externally-hosted content sandwiched between the existing header and footer does makes sense. And yes, an iframed page would solve that.
As a matter of fact, this will be explicitly possible in Verawood using the new frontend-base app architecture (which I’m rushing to get ready as we speak 
). An operator will be able to create arbitrary routes and pages to go with them, all reusing the header/footer if they want to.
It’s actually because of this that I think those specific pages will probably never be ported: they won’t need to be.