I was able to sort of "change" my TVE channels. I saved a copy of the m3u file from my TVE (in my case, http://{server}:8089/devices/TVE-YouTubeTV/channels.m3u) locally. Next, edit the saved m3u file to use your preferred choice of channel numbers (just change the channel-id= and tvg-chno= tags, but keep the original channel values on the tvg-id= and tvc-guide-stationid= tags), then create a new Custom Provider from the edited m3u file. Now, all you need to do is use your new provider with your custom channel numbers instead of your original TVE provider. The only downside is that you need to manually add or delete entries from the file when your provider adds/deletes channels.