To develop any complex and advanced technology you absolutely need other technologies that make that new technology possible. New complex technology could not appear from nowhere, it needs a building bricks made using other technologies. That is how progress works. For any human invention you always will find a lot of traces to the past made from earlier technologies.
If there appears some complex technology without such traces, it means that this technology is not human and was borrowed/recieved/stolen in whole from another civilization with all that technology traces.
There are no any human technologies that could be the bricks for what you talking about. So, if they will do that, it will be a 100% proof of alien interference. Since you suppose that they will do it to fool the people with fake aliens, the reason of doing fake aliens using real alien technology have no any sense.
It is like creating a fake hammer using the real hammer to make people think that hammers exist
To develop any complex and advanced technology you absolutely need other technologies that make that new technology possible. New complex technology could not appear from nowhere, it needs a building bricks made using other technologies. That is how progress works. For any human invention you always will find a lot of traces to the past made from earlier technologies.
If there appears some complex technology without such traces, it means that this technology is not human and was borrowed/recieved/stolen in whole from another civilization with all that technology traces.
There are no any human technologies that could be the bricks for what you talking about. So, if they will do that, it will be a 100% proof of alien interference. Since you suppose that they will do it to fool the people with fake aliens, the reason of doing fake aliens using real alien technology have no any sense.
It is like creating a fake hammer using the real hammer to make people think that hammers exist