Over all the approach you eliminated as too much work is going to be the least amount of work. Create a Group to represent each device, add all the Items linked to the Channels for that device and trigger your rule with Member of triggers.
The DP linked above shows how to make your rule generic so you only need the one rule for all your devices. There is nothing that is going to be be easier or less work. If its PaperUI that is the problem, you might consider trying out OH 3 or moving to text configs for your Items.
