After about 8 hours of wrapping my head around it, I’ve figured it out.
- Make sure your widget properly shrinks and expands in size (I used a scale box).
- Go to your camera and enable “Override aspect ratio axis constraint”
- Set it to maintain X Axis
- On your camera, set the orthographic width to 1920 (Probably works with other values)
- Attach the following blueprint
What a pain to get such an incredibly small thing working.