By "in focus" I mean that prime focus is moved 32mm inward when the coma corrector is inserted.
You can set up the HRCC quite easily. Just dial the tunable top to 13.5mm and insert it into the telescope focuser. Then put some scotch tape or wax paper on the front and focus on a bright object like the moon, Jupiter or Sirius. Once you have it in focus, lock the focuser and use the tunable top to focus individual eyepieces.
Not sure what you mean by "does the ES need a spacer for visual." The ES comes with a tunable top, so you don't need a spacer.
But with the telescope set up with enough in travel for use with the HRCC, you might need a spacer when not using the HRCC, depending on how much travel your focuser has. My telescope (a 12" Skywatcher collapsable) does require a spacer to come to focus without the HRCC. All Skywatcher collapsable telescopes come with a spacer, but you can just insert the HRCC into the telescope focuser directly, without the spacer.
Coma correctors don't move the focal plane inward. They move it outward. I wish they would use better terms, such has "the eyepiece receiver places the eyepiece out further from the focal plane, requiring infocus to compensate".
As for spacers, yes many coma correctors do require spacers for visual. They are designed for astrographs, whose focal plane comes out further relative to the lip so cameras can reach focus. Visual Newtonian have the focuser lip further out towards the focal plane. That means the CC is not placed at the right location unless a spacer is used to place it in further so it can be optimal and come to focus at the same time.
With non opticians writing ads for optical equipment, it is no wonder why several people are reporting aberrations in the center of view. I'm still not confident the ES does not need a spacer. It includes two, but they might be for after the focuser. Something about a T bracket.
