I can confirm that the snake moves at a constant speed using a layer with 100% parallax and multiplying the Move To by delta time.
Although I'm still not sure of how I would implement the Simulate Control action, given that the player character also has that. I'll look into the documentation to see if there's something I'm missing there.
Regardless, thank you very much for your help!
EDIT:
Quick answer to my own question:
Simulate Control works when you do the following:
1. Uncheck "default controls" in the object's platform behavior properties.
2. Make sure the object has not been set in the event sheet to ignore user input.
I may have to fiddle with custom controls to make it as good-looking as Move To, but it does work!