The capability of reordering FX has come up several times in discussions about the differences between Vegas and Video Pro X (VPX). Effects cannot be reordered in VPX.
I have suggested that this be added to VPX as a future feature. Other users have questioned why? It's unusual that we would have to do it in VPX and doing so would just create more problems - downstream effects often depend on upstream effects, so they would have to modified after reordering. In VPX, we can duplicate an object (event in Vegasese) and then remove effects from the original back to where we need to start reordering, and then copy effects one by one from the duplicate and pasting on the original in a different order. Then delete the duplicate. As I say, this is rare.
So, why do Vegas users need this reordering capability? How useful is it? How often do you use it?