Some applications may need to leverage Chromium for rendering content if pandoc isn’t sufficient, which means apps may need to do either of the following:
A) Bundle Chromium with the flatpak application
B) Call Chromium through flatpak-spawn
Here’s an example:
Having Chromium available as an extension would avoid the security issues of calling flatpak-spawn and avoid the maintenance burden of building Chromium.
Adding optional support within an app may look like this: