By default, our editor only lets you create 200 variations per combination of attributes in a product at a time, to avoid overloading your server unexpectedly if the combination of attributes generates thousands of variations.
However, you can increase the number, go to Settings > Advanced Settings > WooCommerce Products > Maximum number of variations per combination of attributes > Enter a higher value.
If the process fails because your server got overloaded, you can repeat it and it will skip the existing variations and only create the remaining variations. This means that you can run the process multiple times until all the variations are created.
The speed depends on your server.
