Text styles and typography variables are powerful - but setting them up takes time, is error prone and repetitive. 

Text Styles Namager simplifies the handling of typography and takes over all the heavy lifting for you.

Create text styles with variables in one click, replace or merge text styles with each other (including external styles), generate variables for your existing text styles and apply to your entire document - don’t skip a node in largest library files.

There are more features I an imagine to add in future - but I don’t want to get ahead of myself.

The plugin includes a free tier and I would be happy if you give it a try and provide me your valuable feedback!

https://www.figma.com/community/plugin/1548356533090301637/text-styles-manager