So I have gone about this in the new way you suggested and followed the tutorial here.
Annoyingly, I have still been unable to get it to work. I have installed SafariViewController and can confirm that is working.
However, when I compile all the files (using Webpack) I get an error:
App.js:139 Uncaught TypeError: Cannot read property ‘content’ of null
Are you able to help? I have updated the relevant files on the same GitHub link.
As before, any guidance greatly appreciated.