As of 2025091000 (AOSP 16, not QPR1) it is not possible to toggle cellular data via quick settings when using a secondary user profile. The toggle is just not there.
But what if I told you that you can actually use the mobile data toggle without having to switch to your owner profile? Even with airplane mode being active? Sounds too good to be true?
Buckle up, everyone!
- Go to your home screen.
- Find an empty space and long press it. A few options should appear.
- Tap on "widgets".
- Search for "settings", tap it.
- Long-press drag "Settings shortcut 1 x 1" and put it wherever you want.
- Choose "Data usage".
- Enter your new widget.
- You have become a wizard. Enjoy being able to turn off mobile data on the fly (literally).
Hope this helps!