> I'd let them know they were free to terminate the lease and move out within a reasonable amount of time...
This would be accurate, but depending on the terms of the contract the tenant may have no obligation to do so, and you would still have an obligation to provide the same quality of lock, secure under the same reasonable threat models, as what was present at the time the contract was signed. In other words, it may be that you would not be entitled to force a smart lock [that adds extra things that compromise the security of the implied threat model such as remote unlock] on the tenant, just as you would not be entitled to remove the lock entirely.
> ...or not renew their lease when it came up for renewal. Being expensive to service is a trait I can legally discriminate against, and is not protected by fair housing laws.
This would be accurate, but depending on the terms of the contract the tenant may have no obligation to do so, and you would still have an obligation to provide the same quality of lock, secure under the same reasonable threat models, as what was present at the time the contract was signed. In other words, it may be that you would not be entitled to force a smart lock [that adds extra things that compromise the security of the implied threat model such as remote unlock] on the tenant, just as you would not be entitled to remove the lock entirely.
> ...or not renew their lease when it came up for renewal. Being expensive to service is a trait I can legally discriminate against, and is not protected by fair housing laws.
No argument there.