I have a Roku Ultra 4661R device (actually 2 of them), and they work fine. I understand how to "replace" a Netflix account with another one. But what I also want to do is to "copy" my preferences, etc. from that deleted Netflix account to the new one. In this way I still have the same lists, etc. of what I have been watching (I watch quite a few Korean dramas on Netflix, and I want to retain them on the new account).
For more information about that channel's features and functionality, you'll want to contact the Netflix customer support team to inquire further. Many channels on Roku are developed and maintained by the channel provider themselves. You can reach them here: Netflix Support.