I would like to not show the category title but a customized title as a subheading on the parent categories.
I know there’s an option now to hide that section under the category title but I would like to keep it ideally and just change it to something that is more user friendly and not cluttered .
There is no option to show categories in the way you describe. There are options in the Theme Settings > Shop as follows:
Option “Categories in page title” will show the categories menu generated automatically based on all categories in the shop. It is not possible to manage this menu as other WordPress menus.
“Show current category ancestors” allows showing sub-categories and category in the page title, for example