I often find that the same scale works for most devices by just dropping type down the scale. So for example, 1.25em text usually used for large blog post copy on desktop would drop down to 1em on mobile. Heading sizes can often remain the same on mobile.

This is probably not the most optimal approach though, since it’s easy to see how the scale might start to fall apart on a TV screen for example.

So it might be better to bake responsive alternates into each size in the type scale? Or perhaps adopt multiple type scales for different viewports?

I’m still experimenting with this issue, not sure which approach I prefer yet.