It would be really helpful if we could also have an "Add Insert Line" feature in Bill like we do in an Invoice. I just love this feature in the Invoice.
When you have the Bill up on screen you can actually insert a line by clicking the Edit Menu and selecting Insert Line (or you can use the CTRL + INS keyboard shortcut).
The Sales Transactions have these two options as well as a Right Click Menu. There are a few complications around adding the Right Click menu on Bills, we currently don't have plans to add it.