To bulk import custom stock statuses for multiple products, you can include the following meta keys in your CSV:
For Simple Products:
in_stock
only_s_left_in_stock
can_be_backordered
s_in_stock
available_on_backorder
out_of_stock
For Variable Products (for Variations):
_available_on_backorder_status
_in_stock_status
_only_s_left_in_stock_status
_can_be_backordered_status
_s_in_stock_status
_out_of_stock_status
Please ensure these meta keys are correctly mapped in your CSV file to import the custom stock statuses. Let us know if you need further clarification!