The backdrop-filter blur on the Mask Editor makes the tool unusable on high resolution when browser graphics acceleration is disabled

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

Be able to use the mask editor without extreme slowdown.
Even if your browser has its hardware rendering acceleration deactivated (to optimize VRAM usage).

### Actual Behavior

When you open the mask editor, it has a blur filter in its background.

This blur effect, induced in the frontend by the line “backdrop-filter: blur(10px);” is based on hardware acceleration.
If, for GPU optimization reasons, you haven't enabled hardware acceleration on your browser, the mask editor is a real pain to use.

We're below 10 FPS on an HD screen and below 5 FPS on an Ultra Wide screen.
There's simply too much surface to blur for software rendering.

### Steps to Reproduce

If you can, try in a high resolution _(eg. 3440 x 1440)_, the higher the worst

1. Go into your **browser settings**
2. In System Tab, search for **"Use graphics acceleration when available"** (or simply type the word **acceleration** in the search bar).
3. Disable that option
4. Restart your browser for the changes to take effect.
5. Open Comfyui
6. Add a **Load Image** node
7. Right clic on it and choose "**Open in MaskEditor**", the modal mask editor window will open
8. Notice the whole background is now gently blurred but your mouse cursor is heavily stuttering

### Debug Logs

```powershell
backdrop-filter: blur(10px);
```

### Other

_No response_

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*This issue is transferred from: https://github.com/comfyanonymous/ComfyUI/issues/8503*

Original issue was created by @Armitage1982 at 2025-06-12T18:52:59.000Z

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-6417-The-backdrop-filter-blur-on-the-Mask-Editor-makes-the-tool-unusable-on-high-resolution-29c6d73d365081d99ea0d191249b9f20) by [Unito](https://www.unito.io)