Looking at your VI, I think exiting the loop is the least of your problems. This VI needs to be redesigned from the ground up as one simple state machine in a single loop that fits on one screen size. Now all you need to do is switch to a special case if need arises. Instead of exiting a FOR loop prematurely, the problem is reduced to switching to a different state in a state machine.
With the current design, you are really painting yourself into a corner. You first need to fix the very fundamental design flaws of your code.
Currently, your VI is a loose collection of isolated statements, many without any defined execution order. What makes you think that the stuff outside on the left will execute before the sequences on the right? How do you guarantee that the various "smart buffers" get emptied before the first value gets entered into them? What's up with the big case structure? Are you running this in "continuous run" mode??? All your "smart buffers" could be replaced with plain shift registers!