I have also been struggling with this same issue. It is ridiculous how poor the quality of UMG rendering in 3D is. It would be great to be able to render a UMG widget exactly like sprites are rendered. The sprite rendering is perfect and sharp and I can move it anywhere in 3D space. I can’t compose blueprint controlled tables with sprites though. UMG is great for building the tables and I can control all the data dynamically, but the rendering looks like crap.
Here is the same exact texture rendered with a sprite (left) and UMG on the right. I’m working on a large project with quite complicated UMG elements such as graphs and tables built in UMG for a hospital.
How hard is it to render UMG widgets the same way sprites are rendered? Is this a big ask?

