Steps to reproduce:

1. Create a new Unity project using the Universal 3D template
2. Create a UI Document asset (Assets > Create > UI Toolkit > UI Document)
3. Double click the new UI Document asset to open it in the UI Builder window
4. Maximise the UI Builder window
5. Click and drag any component to the Viewport
6. Observe the UI Builder window

Actual results: Clicking and dragging the component is extremely slow/choppy and lagging

Expected results: Clicking and dragging the component is smooth and quick 

Reproducible with versions: 6000.3.0a1, 6000.3.0a4

Not reproducible with versions: 6000.0.54f1, 6000.1.14f1, 6000.2.0b13

Tested on (OS): Ubuntu 24.04

Notes:

• Does not reproduce on macOS Silicon Sequoia 15.5
• Does not reproduce if the UI Builder is not maximised
• Also reproduces with other windows, like the Build Profiles window