For a little while, (and I should resume this behavior) I would capture TOS and save them away to read at leisure.
Because what happens, especially with fiddly mobile apps, is that you're granted a single glimpse at the bona fide link to TOS/EULA, and never again will you find how you got there. (Sometimes the link fails right off the bat, giving you zero opportunity to read through the terms!)
So I would take advantage of that and save it, by any means necessary: screen scrape, copy-paste, print-as-PDF, take photo of screen with second device, whatever it took, because they could make it difficult!
But then I would usually end up with a copy of the contract that I could later call up and check on. So, your suggestion that analytics can determine my dwell time on the document when it's presented to me, that's not going to be indicative of how much time I really spent reading it after copying and saving it.
I've found that this is a good practice, and not for the reason you're thinking of. I've found that I'm extraordinarily bad at reading legal documents like this (including my lease, employment contract, benefits and insurance docs, you name it) because even if I think I understand, I didn't get it, and it's pointless anyway because negotiating the wording is not on the table.
But it's a good practice to save these, because of this: there are often instructions included about how to resolve disputes and claims against the company. These instructions usually follow a strict procedure and they have rules about what you can do. They also have contact info, and again, you will never ever find this contact info anywhere else ever again if you don't save the EULA at first opportunity. They will tell you what kind of arbitration or court proceedings are acceptable, they will tell you the complaints procedure from start to end, time frames, and what to expect at each point. This info is gold, and it's not going to be available when you come to have a dispute, and you're not even going to be aware of the procedure at that point, and so you will automatically be disqualified and lose any dispute because you didn't follow procedure. Have fun!
I wonder if they are serving different ToS in the EU (haven't received anything from Microsoft yet).