I have sling on 2 roku 4K sticks. I also use an AirTV anywhere for local channels. Everything works except for an issue with recordings. Playback, skip works, and the vcr style buttons work fine. My issue is that the recording don’t remember where you stopped watching. When you come back to continue watching later the video wants to start over or start at some arbitrary place in the recording.
I went with sling and the AirTV combo is because I can get all the channels I watched on my cable subscription. Scale of 1 to 10 I give Sling an 8, because of the playback problem. I don’t know if this is a roku control problem, or if it the sling app problem.