Thank for sharing the custom component. I took a look at it, but it created an issue as we saw before with the CSS files, which I wasn’t able to solve by removing the leading “./_/theme/” path from the HTML file.
I am curious why I could not use replaceAll() on my button_click event handlers to set the content_panel with the new iframe, however I was able to get the behavior I wanted by first doing self.content_panel.clear() before calling iframe.appendTo() on each button press. Now the content_panel displays a new, single, iframe component with the local HTML file or web address I want.