Hello,
Not sure if you guys are still actively upgrading this, found a issue. When importing(Add/Update) while not using the Name field will receive the following error.
Undefined index: name in /home/gamehead/public_html/vendor/firebear/importexportfree/Model/Import/Product.php on line 396

SKU should be the only required column when importing.
Using very basic .csv file of just SKU - QTY column produces error. When added Name column issue is resolved.