Hello, GreenJersey!
Unfortunately, currently, that is not possible without changing the theme core files, which we don’t recommend. For now,the only way to achieve that is to make a Custom Frontpage Boxes using the Elementor or WP_Bakery page builder(in that case you will need to turn off the “Front page boxes” ).
If you don’t have the WP Bakery page builder installed, you can download it from the next link:
https://mega.nz/#!gUQVQSIJ!vBsKlXI-FJaVwZWCfIiyJktEMXt_OCkct1GySz9u-aQ
Please check the next video guide:
Video Guide
Hope this solution will work for you.
Regards