This is quite an interesting situation.
Your first point about multiple window sensors, if I understand correctly, is something like the following two automations:
- “when any window is opened, set
config/externalwindowopento open” - “when any window is closed, and if all (other) windows are closed, set
config/externalwindowopento closed”.
Is this what you want? This is definitely possible using deCONZ rules only, but the automations in my Hue Essentials app do not expose this functionality in an easy way at the moment. Automation events, conditions, and actions can be customised in the app. But this setup can require a lot of conditions, depending on the amount of window sensors you want to link to a thermostat. A bit too advanced to create using the current features in the app.
How many window sensors do you have in a room? That should give me a bit of an idea what to expect, because there are also limits for the amount of conditions in rules (why these limits were added in deCONZ, I don’t know, it makes it more challenging with even more rules).
I do have plans to add this specific feature, but can not give an ETA at this time. There are a lot of feature requests for the automations and I am the only one adding these to the app.
This part of your request is too advanced for the deCONZ rules. There is no way at the moment to use sensor values (like temperature) as variables, average them, or use them as actions, etc. You would need to find another solution for this, unfortunately.
I understand you may think this is similar to the open/close feature, but for that one you can only have two states (open and closed), so rules can be created for all possible situations. But obviously that cannot be done for every possible temperature value. So something like variables in rules (and basic math calculations) would need to be supported (scripts?), and only then this can be done on deCONZ.