Use case for this is to have a visually containerized(not Docker) HTML such as widgets on native applications(e.g. Windows app or mobile app). As an app developer, I want to limit resource usage of each widget, which is embedded webbrowser. Limitation could be either size of memory or maximum nodes. Once it exceeds the limitation, HTML renderer starts limit rendering or stop creating more nodes or etc and raise JS exception to handle this error.
If it's possible, developers can easily estimate resource usage of their native app better so they can utilize HTML contents in more dynamic ways. For example, X(Twitter) can render HTML5(or WebGL/WebGPU) game embedded in tweet just like it plays a video content embedded in tweet.
Of cause, to make this work, it may require profiling tools to develop and test limited resource HTML contents.
Any standards on HTML standard or discussion on future standards or any tweaks on embedded webbrowsers are welcome.