Large slider which doesn’t change place, buttons to select what you are adjusting. Display the current value on the button if you need it to stay visible.
The magic of software ux is that you can actually replace things on a screen in a way you can’t on a physical device.
There is a reason people serious about doing music keep using physical knobs to change values in their software. I’m entirely convinced the sole reason DAWs use virtual knobs despite them being such a poor UX element is because people will map them to MIDI knobs anyway and that keeps the software and physical world looking the same.
I do it all the time on an iPad. It handles up to 5 simultaneous controls very well.
Prompting the obvious question: Why eleven?
At that point I guess the physical resemblance is a virtue.