Ah, I see.
Thinking scalability now; a simple boolean flag for "in use" is fine if you only have 1 non-standard use for an item. But what if, in the future, you decide to add something else that could also make use of the "in use" boolean? I can see that getting confusing to manage and potentially giving unexpected/unwanted results with the conflict.
So, to keep with logic, you'd just add another bool, right?
How many booleans are you going to be ultimately adding until moving data to a separate table just makes more sense?
I'm not knocking your approach, in fact I quite like it. I merely wish to point out a potential flaw to future designs