Using H1-H5 for your headers and highlight text.
You can format variants and texts to headers sized H1, H2, H3, H4, and H5.
It is simple and easy to add headers to a variant. You just open a variant in a scenario containing text (you can not add headers to an empty variant). Then mark either all text in the variant or just some of the text.
It does not matter whether or not you mark all text since the H1-H5-format are added to all text in the variant no matter what. A drop-down menu will now appear and by clicking on the "Headings" you can add your desired header from H1 to H5.
That was pretty easy, right?