Hello,
You can't change the default dropdown value with the default configuration yet but in their cart they can still add more using the plus button.
In our mind while designing this feature we though that when such use cases require a lot of quantities, shop owners would consider creating bundles of x5, x10, x100, ... depending on what they sell.
If you really need the feature to be able to define the maximum quantity please submit it in the feature requests 😊
