for the most part, selecting a DLC from within the IDE simply opens the folder where the DLC is "installed" on your PC.
IE, the
Giant Asset packs along with the
Sound Pack are simply folders full of media that you can load into your projects, as is.
Games Pack 1 does have a launch app (GamePack.exe) in the root folder that previews 10 of the included games when you run it. a total of 32 games or apps can be found in the /games folder. if i remember correctly, many of them require you to compile them yourself from the included Source Code which is the main reason the DLC exists (the code). the same applies to
Games Pack 2.
the
3D Asset Pack has a model viewer in the 3DView folder. otherwise, the assets themselves are a number of models and textures found in a handful of folders.
otherwise, "libraries" such as the
AGKVR or
Shader Pack DLC will generally have PDF files for you to read/become familiar with along with project/code examples and DLLs where applicable.
selecting the
Visual Editor will, again, simply open the file location where you can run the .exe to launch the program.
so, again, selecting the DLC from within the IDE simply opens the DLC locations where you'll either find folders full of assets or .exes (or both), ready to use. IE, think of the DLC tab in the IDE as a queue of Shortcuts to them. they won't "launch" anything, otherwise.
hope that helps. and, welcome