Hi @circlecube
I think it will be easy if you don’t need to see the result on the flexible content right away. That means that you need to update/save the post, which reloads the editor page, to show the result. To do that, you can create a select or radio field to list the layout you want and then use the acf/save_post hook and the update_field() function to update the flexible content.
If you want to show the result right away, I’m afraid you need to create advanced custom code using Javascript. For something like that you would need to hire a developer to help you out with it, and I’d recommend looking for one on https://studio.envato.com/ or https://www.upwork.com/.
I hope this makes sense 🙂
