Sorry. Thought you were still in the month you paid for.
I use live TV services for sports. I don't usually watch anything else live, and have successfully used those service just like any cable provider when it comes to authenticating apps. Sling does the same thing. I prefer the apps myself, since I prefer the Roku menu to the in-app menu for Sling, Hulu with Live TV, DirecTV Now, YouTube TV, and so on. It's easier for me to launch the ESPN app to watch a game than find it in those live streaming service apps.
I've authenticated several apps, not just sports apps, when I switch to a different live TV service. They all support most apps of the channels in their packages.
Roku Ultra (4660)
Apple TV (5th gen), TiVo, Android TV (MiBox)
Roku boxes from every generation.
Apple TV (2nd, 3rd, 4th gen)