NCH software installs shortcuts to programs, but not the programs themselves unless you install them. The shortcuts take up negligible drive space.
Mouseover the "open app" on the window button and note that it says "click to install and run."

If you click on one of the programs listed in the Start Menu hierarchy, it will prompt for Install On Demand - if you truly want to install the program.
etc.
These are not forced installs. A look at the Windows list of installed apps (Start menu | SETTINGS | APPS | INSTALLED APPS) should confirm that only the programs that you wanted are installed. That's how it is here.