I know many like me are trying to find an easy way to change between TV antenna channels.
Right now speaking into Roku remote with voice button seems like the quick solution. So learn voice commands for Roku.
Right now I found that you can edit the OTA channel lineup on the channel / input settings on the settings section found on Roku home.
I hope this helps.
Just a tip. I know this is an older post, but you can say tune and then the channel name like one here for me is KPLR and it’ll change to that channel.