It would be really useful to be able to add a note to lines on Purchase orders.
Example 1:
With so many items still out of stock with suppliers it would great to put the expected ETA of parts on each line when they are out of stock. This would help when booking in deliveries and allow you to see what's coming and when from an order at a glance.
This would be doubly useful if these notes were visible in transactions in POS as back ordered parts would have an ETA that's easily visible when the job is opened.