I submitted this as an idea some time ago. I hope it gets implemented!! The more people give it a thumbs up, the more the developers will look at it.
https://community.esri.com/t5/arcgis-pro-ideas/table-of-contents-toc-formatting/idi-p/932648
Awesome, I gave it a thumbs up!
Hey Product Manager! @DanielStone
Thank you Brent. Always on top.