I would be interested in paying for a Channels Viewer app that provides scanning channels, channel guide, and viewing live tv without the dvr function. I have looked for an app for macOS similar to the ios and apple tv apps.
Are you using an Apple Silicon mac? On mine, I can use the iOS full app (DVR client) just fine. Would that meet your needs?
I am using an 2014 Intel imac. I know that hdhomerun has an application, but it doesn't work well with the intel mac -- mostly the lip sync on the sound is off and I haven't found a way to sync the sound up with the lips yet. Channels does a great job on the iphone, but they don't have a viewer app for the imac. Plex is my only choice on the imac that handles the sync correctly.