Shuttle can always send each Shopify variant's quantity to its matching Etsy variation, whatever stock setup the Etsy listing has today. Each variation on Etsy then shows its own stock, which is ideal for detailed stock management.
How it affects existing listings
If an Etsy listing tracks stock at the product level, Shuttle converts it to variation-level stock the next time it updates that product from Shopify to Etsy.
This setting applies to product updates from Shopify to Etsy. It does not change how real-time stock syncing handles listings that track stock at the product level. For that, see Handling Etsy Stock Management by Product or Option Level.
Enable this option
In Shuttle, go to Settings → Products → Shopify → Etsy and scroll to the Stock Quantity section.
Under Variation-level stock, check Always update Etsy quantity at variation level.
Click Save.
If you don't see this option, Assign quantity at product level on new transfers is checked in the same section. Uncheck it, and the variation-level option appears.
Important: If you prefer to manage stock at the product level instead, see Simplify Inventory Management by Setting Product-Level Stock Quantities on Etsy.