Hi @thomas,
Since you are currently working on the new phase of WooCommerce, I hope you don’t forget the add to cart widget.
Unfortunately, there is currently very, very limited customization for the Quantity section of this widget.
If you want a great example of this widget, I recommend jet woobuilder. This plugin has an addon in which it is possible to fully customize the Quantity. (this addon download Link) I suggest you check this plugin to develop this widget in the best way in bricks.
I hope you read this thread.