Shopify POS at 2+ Vendor Markets? Now have Shopify Storefront.

[Pb0731]

I currently have a Shopify storefront and also sell at Vendor Markets which requires I stock inventory. I now use Square at these markets to track this inventory which is tedious. How well does Shopify POS Basic work for Inventory/restock alerts and to use at more than 3-4 locations?  Thanks.