What is the best way to switch video sources

I have a number of activities working that all assume everything is off in the beginning state. Once I have the TV, AVP, and amps on, I'd like to be able to simply switch my HDMI video sources without powering everything down and starting up again with a new Activity. In many cases, all I need to be able to do is send a command to the HDMI matrix switch to select a new input. However, in a couple of cases I also need to be able to power on the new video source video (e.g., watch a CATV source and want to watch a BluRay). I've tried a couple things but neither has worked satisfactorily.

1. I tried setting a new Activity to power on the new source and switch the matric switcher but as soon as I select the new Activity, it triggers the set of Stop actions that are defined for the first activity, so my TV, AVP, and amps all turn off.

2. I tried using Design to add a custom button for each video source. I have it working where the button can switch the matrix switcher and turn on the BluRay player but I don't see a way to make the new video source the primary device so its controls show up on the iPad.

What is the best way to switch video sources without switching everything else off and on?

In theory all activities have to assume the beginning state is off as it could well be and thus needs to turn everything on (I'm sure there are exceptions where conditions can be used though). I think the issue is that you have 'Stop' actions. If you remove those, nothing will turn off when you select a different activity, although to save on energy, you could keep a stop action for the device the activity relates to i.e. if the device that isn't required in any other activities).

The system off activity will turn everything off when required.

Selecting a new activity will simply turn everything on (if they are not already) then switch to the relevant input etc.

A potential issue with this is for example, if toggle is the only power control for your TV. In that instance starting a new activity would actually turn off the TV if it was already on. There is a way around this by selecting an option to track powerstate in the device settings, but it will come out of sync if someone turns the TV off with the remote.

I do what @mbells suggests. Each activity powers on the needed devices. The Power Off activity for the room turns everything off. I suppose if you know for sure that you don't need a device on for an activity that you could issue the device a power off command from the start of your activity. For me I always have the TV and AVR on and the rest is just switching matrix and / or AVR inputs as needed and turning on the source device. To me I don't mind if two or three source devices are on.