Short answer: no.
Long answer: Roku's old "private channels" are called non-certified apps/channels. During the old "private channels" days, Roku did not have a limit on them. The idea was a "private channel" would be for the developer to get the app out there until it got certified into the Channel Store.
With many developers leaving apps as Private Channels, circumventing Roku's intent, Roku revamped the process a year or so ago. A non-certified app (Private Channel) can only exist for 90 days, until the app is certified.
That's not necessarily to say you can't find some way to accomplish what you're after, just to say that Private Channels is not the way.
Roku Community Streaming Expert
Note: I am not a Roku employee.
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