It seems to be working - I didn't realize that when you click Synth, it moves it to the VSTi list. Because it disappeared from the VST list, I thought it was just gone. But it was working; I just didn't know it.
I still don't see a way to check both the box for Synth and Tempo-based effect, but that doesn't seem to matter; as long as it's in the VSTi list, all is well.