His theory functioned as a working hypothesis, as all theories do. But to my knowledge he did not question the MI-Reality of objects, and this is a point which causes conceptual problems at present. I doubt that. I think it is your projection, just as your view of my approach seems to be mostly your projection. At Newton's time this was not a crucial point.
Objects is, at best, a kind of shorthand.
I think Heisenberg is giving up too much here. I would clarify that the arbitrary and capricious introduction of mind that you and Stapp advocate is an ingenuine subjective feature. Genuine subjective features are precisely those that do not take excessive pride in their subjectivity, but rather acknowledge the ultimate oneness of subject and object in transcendental reality. This was the view held by all the founders of quantum theory. It is well documented in all their writings.