EXR renders won't go above 640x360 when rendering from an Editor Window

User was attempting to render out EXR sequences and ran into an issue where anything above 640x360 caused the window to shrink and render at a lower resolution.

The workaround is to "Use Separate Process" with the -ForceRes command, but these resolutions work for other render formats (PNG and BMP).

1. Create a Matinee or Sequence
2. Create a simple camera that pans
3. Create a director or shot track
4. Select Render Movie
5. Change Capture Type to "Custom Render Passes"
6. Set your Frame Rate to 30 and Resolution to 1080p
7. Add the "Final Image" render pass
8. Enable "Capture Frames in HDR"
9. Ensure that "Use Separate Process" is disabled
10. Capture Movie

Result: Rendered frames are lower res than 1080p
Expected: Rendered frames are 1080p