Security on F4106 for non stock items - line type N

We currently have row security applied to the base prices file F4106 using branch plant.

As we are looking to set up non stock items, these have no item branch record and are set in item master to apply sales price at item level not item branch like our standard items. With our current security the non stock items are not getting a base price when entered on sales orders via P42101 as the MCU for the non stock items in the F4106 table is blank.

What is best practice when applying security to the F4106 to allow successful pricing of the non stock items?