For merchant who has long list of menu items and want a scrollbar to scroll inside a submenu.
There are reasons why we DON'T recommend users to add a scrollbar to a long menu:
Although we provide a features to allow you to add scrollbar inside a submenu, we still do not recommend to do it, because:
Confuse users: Browser already has its own scrollbar, so if we add another scrollbar it will confuse user sometimes, making users not know which scrollbar to scroll For example: User is hovering on menu and wants to scroll down the page, but it will scroll down the menu instead.
User might not scroll down: The purpose of a mega menu is to show all items for overview and quick navigation, so you shouldn't hide items in a scroll menu. The chance that user don't scroll menu is very high.
Increase searching time: To find a category item at the bottom of a submenu with a scrollbar, user needs to hover or click on the top menu item to open submenu, scrolldown to find a menu to open, it takes around 5 seconds to find a correct target.
Therefore, we recommend to find another way to organize your menu to avoid scroll.