I have a client who prefers to have very detailed invoices, and we only bill them monthly. So, it's possible that they might have 40 projects or line items on a given invoice.

Using the little up and down arrows to arrange the projects in a way that makes sense takes too many clicks.

Any chance we could get a draggable handle to drag and drop projects or line items on an invoice up and down instead of having to move them click by click?