Failed to change the hot key for zoom in/out

**Describe the bug**
Setting the env var
`EDITOR_KEYMAP: '{"tool:zoom-in":{"key": "shift+plus","description": "Zoom in on the image"}, "tool:zoom-out":{"key": "shift+minus","description": "Zoom out of the image"}}'`
Inside the app container, I can see the env var is correctly set. But the UI has no change and this custom hot key doesn't work.

**Expected behavior**
The doc https://labelstud.io/guide/labeling#Customize-hotkeys claims these keys are all customizable.

In addition, the default keys `ctrl + plus/minus` conflicts with browsers built-in zooming keys. Do you consider change the default to something else?