Once you've opted in to making SKULabs the master of inventory for your store, we control inventory levels for all products on that store.
Fortunately, through the listing stock and price rules you can control individual listings using a rule skip in place of the store_default default rule.
For advanced users looking to opt each listing in individually, you can set your store stock sync rule to skip then override store_default with free for tight control over which listings SKULabs manages inventory.
You can configure listing rules on the listing's page. To find all listings associated with a SKU in SKULabs, open the item then scroll to the listings section. From there, open each listing then edit it's stock rule to the desired value.