To be clear, I do not have any misapprehension that Refitting can be done partially, stopped, and then resumed from the point of stoppage. In Alliance rules something must be fully successfully to have any success: 100 Obliterate does nothing to you if your card says you're immune to damage in even numbers, and you must complete your three count or minute or whatever or nothing happens and the ability is, if applicable, expended; the only extant exemption to this is the introduction of animation effects pausing death timers which is entirely a customer service decision. That sentences was too long and I am sorry, but not sorry enough to fix it.
That is actually the point of my interpretation: a refit in progress on a suit of armor should not allow you to mitigate the effects of a Shatter. If the other version is correct, then I am able to game the system by beginning a refit prior to a Shatter effect if I know one is coming. I'm not arguing that that is a common occurrence, but I am arguing that it should not resolve that way. If I am wearing a 50 point suit of armor that I can refit in 15 seconds, then I am functionally immune to damage that arrives at less than or equal to 10 points of damage over three seconds if I choose to simply kneel and constantly refit. If I am doing this in a doorway with archers/casters behind me this starts to become silly.
I feel pretty strongly that this is a case where the fundamental assumption that you cannot successfully repair armor that is being actively damaged did not even occur to the writers as something that could be called into question, because if someone had said to me that the new system would allow for this I would have made every other owner miserable until it got changed.