re: Using your analog...till they can make round ones. But this is looking for new blood...
more than invention. Did you happen to look at the various parts of the PDF I was so interested in? I suggest you look for the word bruises (a guess).
The problem with any suit and especially zero per breath (higher pressures) is the usefulness of your hands and in particular your metacarpal joint of your hand.
I suggest anyone interested in this spacesuit design problem reading Design and Structural Analysis of High Mobile Space Suits and Gloves.