I understand how the column you're looking for is beneficial to your business. Right now, the ability to include SKU when printing purchase orders are unavailable.
For Purchase Orders or any other vendor transactions, you can enter the SKU on the Description column (see screenshot below). To ensure your voice is heard, I can personally submit another feature request on my end.
In the meantime, you can visit our blog and sign up for our Newsletter. This way, you’ll receive email updates about changes in the product.
Drop me a comment below if you have any other questions or concerns. I'm here ready to help and make sure you're taken care of. Have a good one.