I may have a solution for you, but it depends on what you need to do with inventory tracking.
If you only need inventory tracking to view how much was sold, then you could disable inventory tracking and still run an item sales report to see how many of an item was sold in the given time period.
However, if you're using inventory tracking to prevent overselling (particularly with online sales) or manage your stock without physically looking at it then this option wouldn't work for you. It also doesn't work if you require COG reports, though I'm not sure if that's needed with consignment pieces.
For example, I don't use inventory tracking for my loose leaf tea because it's impossible to account for small spills or overfilling a bag by a tenth of an ounce. I still use the item sales report to see how much I sold. The only major downside is that I have to keep an eye on my storage shelves to know when we're running low on something, then manually mark it as sold out in Square.
I am hoping that Square introduces a custom field for inventory changes. I often remove inventory to put in bundles (which is another feature request) and I mark these stock changes as "theft." I haven't knowingly experienced theft so I never use that option for its intended purpose, but when I run a report I know what it means by theft.
