Payment terms default on Sales detail lines

We are running into few issues when we try and activate the adv pricing to default payment terms on sales order lines in 9.1 release. We just need to default the term which is "no payment due" for our free samples, warranty orders, etc. We have separate sales order types for these activities. However I am not sure if we can activate payment term based on the order type, please advice. Now, with no alternative to default payment terms by sales order versions or order types, we have to set the preference master P40070 and the pref type as 01