Notes on orders and/or over-ordering

-- HikaShop version -- : 4.0.3
-- Joomla version -- : latest

A customer who has started to order a number of times has asked if there is a section within the ordering system that would allow them to add notes.

For example, they ordered yesterday, however, they wanted to order greater than the stock quantity. Currently, you need to order the stock amount, then forward order for the extra quantity separately.

If there was a comments/notes section, this would allow him to inform us to hold the original order until all lines are available, allowing consolidation of goods.

The alternative and ideal situation, would be to allow him to over order on the line, however I believe this is not possible with Hikashop.

What do you suggest is the best option for this problem.