Today most of our screens support a 1920x1080 resolution.
And the actual space that I can basically use in the MHL is 530x315 pixels (roughly, surface of the MHL minus subdiagram comment).
Which means that my useful coding surface is only 30% of my screen resolution.
I guess the EHL and MHL can be designed wider so that we have more space for our custom code.
After much discussion, we agreed to accept this feature request with the following clarification: