What is it exactly that you want to change about the chapter as a result of the decision the learner makes?
To have complete control over branching, you have to have two things: 1) ways to get your learners to where you want them to go, and 2) ways to shut down the other options.
You can achieve #1 through links and internal links, but because you can’t fully operate on the chapter structure using variables (yet… it’s coming) — like you can’t hide chapters or change any properties of a chapter using a trigger — you’re better off using content morphing.
I haven’t seen the source content for this part yet but can you direct them to the next chapter and then when they get there, it’s content morphed? CM works across the whole PeBL, so the decision point or the thing that triggers the morph doesn’t have to be right before. It can be anywhere in that PeBL.
I’ve found that I can do the style of branching scenarios where learners are always being directed back to the main path quite effectively with CM, but if you want to do the style where they really are going to be able to go far down different paths, it might require more ability to manipulate chapters, which is coming.
PS there are actually names for the different styles of branching I mentioned… I think you would like this but of ISD geekery so I’ll try to remember or find them!