In an effort to expand the color palette you mention consider this; everyone seems sold on the fact that the only function for this balloon was gathering data of some sort or other. Either gathering weather data (seemingly harmless) or intelligence data regarding our military capabilities. What if they weren’t looking to collect something but experimenting with DELIVERING something. Had that balloon been carrying a biological weapon or a nuclear device once it crossed into our airspace it was successful whether we shot it down and released its payload or the ChiComs pushed the button. There’s just as good a chance that this balloon (or the next one) was a giver as opposed to a taker.
Or release tiny drones carrying who knows what payload
If the CCP balloon was delivering anything, I’d bet it was crop diseases. Seems like a practical way to do such a thing. Sprinkle a trail of small particles which were inoculated with virus and/or fungus, and it wouldn’t be detectable visually or on radar.