Yes, the SCTL will cause your usage to go down. The reason is that the SCTL causes LabVIEW to remove a bunch of buffers inside of the loop. It can do this since all of the code inside of the loop will execute in a single FPGA clock cycle.
Your code with the SCTL will not work as is. You need to wire in a TRUE to the termination for all of your SCTL. Also, you have a rotate array inside of a SCTL, which won't work.
Quickly looking at your code, you should be able to use just a singe SCTL to encompass all of your code (instead of your big while loop). You just need to work around those Rotate 1D Arrays. That is simple enough by keeping track of which element you want to replace. So instead of rotating the array, you just circularly replace a different element. We might also have to work around the FOR loops that add up your fixed point numbers. I have other thoughts for that, but not formulized enough right now to put down.