Composite results in preview window?

Is there a way to create a preview window in a panel/popup and show the “Render Result”? Would like to show updates when changes made in the compositor.

This is all I can come up with ,but has issues.

1: Render and save each time a change is made
2: Load as a icon
3: Use col.template_icon(icon_value=my_icon, scale=20) to create preview

Issues

1: Delay when changes are made and “preview” is not real time
2: Preview resolution is low