There are use cases where Forge apps have a valid reason to display something fullscreen. Think of Wallscreens. We develop an app that creates slideshows that can be presented directly in the browser.

Currently, Forge apps can not display any content fullscreen, meaning either a modal that covers the full viewport or opening a new browser tab.

I suggest that one or preferably both of the following solutions are implemented:

• Create a new size parameter for the Custom UI Modal named "fullscreen" that will show the modal in the size of the whole viewport. (As a side note, that's what I would expect of the existing parameter "max", but instead of 100% as stated in the docs, it rather covers 80% of the viewport.)
• Create a new method in the Custom UI router that opens a Custom UI resource in a new browser tab.

This sounds like a small thing, but blocks a whole class of apps from migrating to Forge.