Every time a common property key wanders off with a former resident, the security of your building is reduced. That’s why Owners Corps demand a deposit that you can then pass on to your tenants.
I really don’t see the problem here – it’s costing you nothing and its preventing the security of your and other owners’ homes from being compromised.
If your tenants can’t be trusted to return the key, maybe you are choosing the wrong kind of tenant.