First, the activities only know that the device needs to be on a particular input. It's the device itself that's responsible for figuring out how to get from the current input to the required input. So activities aren't the problem. The problem is the device thinks it can go directly to the digital or analog input by pressing the TVMODE button - but that's not correct. It only takes you back to the previous input which as you said is a 50/50 shot. So it's the device input setup that's incorrect.
Once you setup the clone TV device to use an input list to cycle between digital and analog then the harmony smart state will remember whether it was on digital or analog and it will dynamically figure out whether it needs to switch from one to the other depending on where it was.
Setup the main TV device with discrete inputs - HDMI and a bogus input with a bogus command that does nothing.
Watch DVD - main TV device on HDMI input, no clone device Watch Digital - main TV device on bogus input, clone on Digital input Watch Analog - main TV device on bogus input, clone on Analog input
