We'eve just pushed an update to our EZ Inventory app to provide an option for case-insensitive matching when perofroming variant lookups by SKU, barcode, product title, or a custom variant metafield value.

We've seen a few cases in the past where the supplier's feed may use all uppercase for the SKU while the rmerchant may use all lowercase in Shopify (or vice versa).  We already have an option for manipulating the supplier feed data before doing a lookup via our product mapping formula feature, so you can auto-convert the values to all uppercase or lowercase in this particular scenario.

However, we've recently encountered a scenario where the merchant uses mixed cases for the SKU in Shopify.  For example, they may have a SKU like "BrownShirt-Green_XXL".  So the product mapping formula feature won't work in this case as it only manipulates the supplier feed and if the supplier feed uses all uppercase, we can't convert it to a value that would match the Shopify SKU exactly as there's no consistent pattern (i.e. we can't even use titlecase via .title() because it would convert the "XXL" part to "Xxl").

An "Ignore case" option is now available to handle this scenario, so the merchant or supplier can use different cases and the lookups will still work.

You can find this option when configuring the Data Feed under the Field Mapping > Additional Options section as shown below:

The option is disabled by default as in the vast majority of cases we've seen, the SKUs in the Shopify store and the supplier feed are identical.  Shopify also does allow duplicate SKUs and some mercants may use the same characters in the SKU but with varying cases and treat them as different SKUs.