Sync " Contact Name" to Purchase Order #

I use OneSaas to sync WooCommerce/MYOB. One choice is to " Populate Purchase Number with Invoice Number" , this maybe use to some, but the Invoice Number is sync'd already as Invoice Number and populating the Purchase number just duplicates the data. 

Many business small business that don't run a PO number system use the " Contact Name'  as a PO#, to have a tick box in the set-up to choose " use Contact Name as PO#" would be very useful.

Craig