I think this is a valuable switch of perspective, but taken together the bulk of these techniques sound like “write your own specific mocks instead of using a mocking library” to me
I think there is a difference still, perhaps just in that the scope of the “mocks” is smaller, but a more thorough explanation would be good.
There’s a lot of interesting material here (more than I’ve fully digested), but a lot of the specifics seem debatable. To take one small instance, colocating test factory methods with the production code seems odd. The advantage is a minor increase in ease of maintenance, at the cost of polluting your API. I’m not sure it seems like a worthwhile tradeoff to me.