Why must we have this? Why won't it collapse like every other thing in the design tree?
Why is it special and not following the normal mechanics of the tree UI?
Why does it not have its own category that also is collapsible?
How do I ensure that my models do not have this issue going forward?
Those don't have anything to do with Construction, they are just located near the Construction folder in the browser. They are not "events", they are Direct Modeling Features. This is a Direct Modeling Design. I don't know why they do not have a folder. If you don't want them, you can select them all and choose "Dissolve". It will not affect the geometry in the model:
There is some history here: Fusion started out life as a direct modeler only. Part way along in development, we realized that you just could not do everything with Press/Pull and Move Faces. So, we added these "direct modeling features" to try to make some kinds of edit easier. You can right-click on some of those features and "edit" them. It doesn't always work, and whether it does depends on what other features have been added to the design. For instance, if you create a hole, you can most of the time edit it. The "edit" here is really just: get info about the hole from the geometry (depth, diameter, etc), delete the geometry created by this feature, and re-invoke the Hole command, filling in the depth, diameter, etc).
The other thing you can do is use them as a way to select the faces created by this feature. Try it: create a direct modeling fillet, and the faces created by that fillet will be selected. This is useful if you want to "delete" the feature, for instance, or set its color to red, etc.
