I don't even want to put IO into the device at all. Not only because it increases cost and size, but because I don't what the user having to interact. We have to find better ways to fit the device in your life, so you don't even think about it.
There is a ton of snake oil in the industry, and I see so many people building similar products, that take the language of the research papers, and apply it to absolute nonsense.
There is over a decade of research in slow-wave enhancement, Philips funds a lot of research in this space, and even had a slow-wave enhancement device out in 2018/2019.
I'm not sure if what you are asking is "are we snake oil", or "do I get people asking". But in general, I hear so many people talk about grounding mats (no scientific evidence), EMF, neuromodulation to put you to sleep instantly, and so much other garbage, that I wish people would question things more.
I wish people knew how to read a basic research paper and decide if it even says what the company is claiming. I'm amazed that a company can put up a page that says "science", with a picture of a person in a lab coat, and people go "ok, must be true".
We're on a long view of this, and while VCs are dumping tens of millions into snake oil "neuromodulation" companies, we're taking a slower approach and playing the long-term game.
I'm keen to hear your thoughts.