Reproduction steps:
1. Open user's project "UIToolkit2.zip" and open "SampleScene"
2. Open additional Inspector window by right-clicking on any window tab and selecting "Add Tab"
3. Click on the "PanelSettings" asset in the Project window so it appears in the Inspector window
4. Drag this additional Inspector window somewhere, so you can see both Inspector windows
5. Lock one of the Inspector windows
6. Click on "Directional Light" in the Hierarchy window, so it appears in the Inspector window
7. Compare how text is rendered in both of these Inspector windows

Expected result: Text is rendered absolutely identical on both windows and there isn't any difference
Actual result: Text is rendered differently in the "PanelSettings" Inspector window, it appears a bit more blurry and less crisp

Reproducible with: 1.0.0-preview.11, 1.0.0-preview.14 (2020.3.5f1, 2021.1.4f1)
Couldn't test with: 2018.4, 2019.4, 2021.2 (UI Toolkit package is not available)

Notes:
- See reproduction video for pixel comparison of the text
- In 2021.2 UI Toolkit runtime is included in the Editor itself, but it doesn't use TextCore, so it renders text with TextNative, which results in identical text rendering
- In newer 2021.2 versions the TextNative renders much more of the text in the Editor UI, resulting in blurry text in (see attached image "Editor2021.2.png"):
1. Project window search bar text is slightly blurry.
2. Scene View overlay texts (Center, Global, 2D) are blurry and hard to read.
3. Fetching Packages in Package Manager is blurry.
4. Package names in the list are blurry.
5. Package authors are blurry.
6. Package info box is blurry.