Yes, SiliconDust guide data works with ATSC method. If you are serious about switching to ATSC mode, you should just start from scratch...
Disconnect the Client from the Server library. Reset all TV setup and disable ALL SliconDust tuners on the Client. It will get everything from the Server.
Then create a NEW clean TEST library on the Server - Run through TV Setup using ATSC method, disable DMS tuners, run the scan, setup channels and guide. Test playback.
Now, on the Client connect to that NEW clean TEST Server library. Don't run TV setup and verify the SiliconDust tuners are disabled. You should not see any tuner profiles on the Client. Go to Guide and try to play a channel.
So, I backed up both my server & client settings and libraries.
I exited the client.
1) I uninstalled/reinstalled MC31 on the server.
2) I went through TV setup on the server, using the ATSC tuners.
3) For the guide, I selected SiliconDust .
4) It told me to enable DLNA, restart MC, and run TV setup again
5) I did, and proceeded with the channel scan
6) It found the same list of 5 channels I posted earlier - 7.1, 7.2, 7.3, 7.4, 4.5 .
7) Unfortunately, it also found channels using TunerStream, even though I had never told MC to use them. I can't tune to any of the ATSC channels, however. There is no signal lock.
It looks like enabling DLNA in step 3 to get the guide caused the TunerStream tuners devices to show up in TV devices, unfortunately.
So, I repeated these steps, except in step 3, I chose "no electronic program guide".
At that point, the channel scan found the 5 ATSC channels. But I can't tune to any of them in the server GUI. It looks like the ATSC tuners just aren't working at all with MC31, even with the server alone, so there is no point in trying to further share them with a client.
I also installed a trial version of MC33. The channel scan found all the channels through ATSC. And I'm able to tune to all of them in the server GUI !
I am also able to tune to all these channels in my MC31 client.
So, it looks like there are two issues :
a) TunerStream tuners can't be shared successfully with the client
b) the ATSC channel scan and tuning fails in MC31. But that bug is fixed in MC33.