Again just my two cents but I am not sure that having two Power Masters is required or advantageous. Just connect the two 180 watt Power Blocks, in Parallel of course, to one Power Master. That will give you 360 watts all over your layout for your Locomotives. This would also allow you to use the BPC2. The BPC2's would allow you to turn on/off any block on your layout. If you used two Power Masters you would then need to use the BPC. But then again if you are only using Command Locomotives, why would you want to switch between two different Power Masters? Again why insert that complexity for a reason I can't figure out? If you have a "For Instance" in the back of your mind that maybe I am not considering, get back to us.
Again the beauty of Command Control is not being stuck behind a "Control Panel" using the BPC2's will allow you to do that. Using the SPST hamstring you to remaining behind the "Control Panel" to flip them when you need to. If you are still 7734Bent on using manual switches and you are using two Power Masters, you would actually need to use SPDT (with center OFF) switches as the center position would be no voltage flow and the Double Throw would be one way connected to Power Master One and the opposite throw will be connected to Power Master two. This would allow either Power Master to be connected to the subject Block. One SPDT switch per block is necessary.
I hope this helps you somewhat.
