I finally got PlexConnect working on my appleTV3. It's great.

I didn't realize that the new ATV profile could be installed WITHOUT USB, and I followed the Apple Configurator instructions on the Wiki.

However, I tried a few links and actually could not find the original version of "Apple Configurator", only "Apple Configurator 2" on the App Store.

The process is essentially the same, but instructions are a bit different.

I'm placing them here, and will be happy to update the WIKI if someone gives me acccess to github.

Apple Configurator 2

1. From the File menu, select New Profile.
2. On the General tab, give the profile a name.
3. Click the Certificates tab at the bottom.
4. Click the Configure button and select the certificate you created earlier and then click Open.
5. From the File menu, select Save.
6. Plug in your AppleTV to a power source, then connect it to your Mac via micro USB. It will now appear in the Apple Configurator Device window.
7. Click the Add button at the top. Select the Profile you created above. You'll see some activity as the profile is added, including a status dialog. Once that closes, you are done!