The Quantity Breaks (standalone) app is no longer available for new installations. If you are currently using Quantity Breaks (standalone), you will be able to continue using the app on a grandfathered plan.
Any new installs of the Quantity Break app will be redirected to Custom Pricing which has a Quantity Breaks plan available. For more information on Custom Pricing, please visit Custom Pricing: Information and Overview.
The short answer is no. Visit Delete Quantity Breaks Variants for the proper steps to remove the variants.
Note: If you want to process any imports and exports, do this with the quantity breaks group disabled. Once this is complete, you can turn it back on. Any changes you have made will automatically be applied to the quantity breaks groups.