On the right and left of the numpad is a lot of space, we could change the 'switch to candidate button' into a switch toggle with labels and put it left or right of the numpad.

See here as an example of such a switch toggle:


We could also move the numpad to the left or right, based on user preference. When they are left-handed, we should put it on the left, if right handed, we should put it right, for easier thumb access.
I think there is a browser preference for left- or right handedness which we can use to change the layout of the area.
(Similar to : dark-mode and prefer-reduced-motion)
This has to be researched.
On the right and left of the numpad is a lot of space, we could change the 'switch to candidate button' into a switch toggle with labels and put it left or right of the numpad.
See here as an example of such a switch toggle:

We could also move the numpad to the left or right, based on user preference. When they are left-handed, we should put it on the left, if right handed, we should put it right, for easier thumb access.
I think there is a browser preference for left- or right handedness which we can use to change the layout of the area.
(Similar to : dark-mode and prefer-reduced-motion)
This has to be researched.