For those that find this question is asking something that they are also struggling with, the answer was the 'embed' tag
You will need to place the element into a structural holder (eg div), and remove and recreate the element in JavaScript to get it to vanish and reappear if you want it to reload on show.
Pages loaded in this way do not inherit CSS theming, except background colour (if no background colour set). It does pick up @media settings, but only from the browser. This is intended behaviour.
Ultimately, to get the full functionality, I am going to have to redesign these items to be part of a single page, loading the data in piecemeal. However, this fix gets me a functional way of achieving something I need quicker than a redesign.
Thanks,
-BX