You're right of course. I'm experimenting with different effects.
A plausible scenario for using this kind of setup: the user hovers over a menu item and the menu item morphs into something else. As in the example provided by afrlme in another thread.
Morphs into another item? Which thread?
I also call snoop animations hotspot indicators. I think a long time ago that the VS dev time somehow came to the conclusion that they should call them snoop animations for some reason or another - VS is a German game engine by the way & all the devs that have worked on it have been German, so it's probably just a lost in translation name & no one has bothered to rename it.
Anyway, I agree with Esmeralda, the semi-circle indicator is a waste of time as you already have inactive & active state mouse cursors to let the player know when they are hovering over something they can interact with, & you can use the snoop (hotspot) animation system if you want to provide the player visual aid on what they can interact with in each scene.
Oh, before I forget... you could technically include the semi-transparent semi-circle inside of the active state of the cursor(s). The interaction position is defined by the animation center you specify, which means that if you were to set the position on the same pixel of the cursor for both inactive & active state cursors that they should be aligned correctly without shifting position when changing between states.