Concise and clear answers, very nice! I think I’m getting better at understanding Scottish also! 
Btw, I always find that when talking about the inventions, there’s a grey scale of what would constitute an “invention”. There are some other stuff that I haven’t seen out in the wild, that seem complicated and time consuming to get right:
- Farming rewards / network economy (How to have it resilient and sustainable).
- Client side access control. (How to definitely control what can be done by the apps).
(Maybe something else as well from the currently unsolved questions?)
I kind of consider these two things “inventions” as well, if the prerequisite is that it hasn’t been done before. And I would be inclined to add “major” in front of them as they are both essential and in my estimation will take a lot of effort to get right. But, it’s a gray scale. Maybe it’s useful to rate these things in other terms.