It looks like you need to press very hard. I expect that people's fingers will get tired and stiff.

Why not just take a picture of your paper? Ideally, they could just put some special markers on the corners of the page, and then a phone app could home in on those to properly focus and align the page. Problem solved.

The other thing is, why make the pen communicate with the device (e.g. tablet) in real time? This seems like a waste of power, and not practically useful [1]. You could simplify it by just having a button on your pen that, when you click, sends over the aggregated line data.

[1] I suppose one use case is to share in real-time with some kind of audience, but this is already a solved problem with a stylus on a laptop or tablet... why add the extra cost of special paper?