The short answer is no; our Output Engines are not designed to offer users the ability to add their own samples. That being said, it is technically possible to add your own samples with a decent knowledge of Kontakt's inner workings (and the paid version of Kontakt). Output does not support this or offer any additional advice on the subject, but you're welcome to give it a try!
That said, you can load your own samples inside ARCADE. Check it out here.