When you have saved a FX-Preset and want to save it again (after some fine-tuning), you have both of them... old version and new version with the SAME name. If you don´t need the old one, you can delete it, but you never know, which of the both is the old one.
So it would be good to have the choice to "replace", "rename" "save as", when saving the Preset... just like when saving a Rig.
Martin