I like this implementation. Could we pass it to be part of the ButtonPill and ButtonPillToggle components?

So, adding the stringContentVariations array as a prop to ButtonPill and ButtonPillToggle. It should be undefined by default. But if it is defined, then we should invisibly print all the variations in hidden mode as you did in this implementation. So the consumer would use it like this:

<ButtonPill
    scale={20}
    stringContentVariations = ['long', 'longer', 'longest']
>
   <Icon scale={28}/>
   <Text>Hello</Text>
</ButtonPill>

ButtonPill will know its own size. So from there, you can deduce the icon scale and text scale the invisible prints should have (nice work on that util btw!).

What do you think?