Does hair canvas need to extend into the lapel?

Once again I'm confused by what I see online and can't find an answer.

On the coat I'm making, I'm interfacing it with hymo, hair canvas, and domette. What I'm wondering is, does the hair canvas need to extend into the lapel?

I would think that it does so that when pressed, the hair canvas would really help the lapel stay folded over. But on some tutorials I've seen, the hair canvas is cut off right before the roll line, so that there is only hymo attached to the lapel.