I'm not getting what you're saying. The attached picture talks about the build game and how you have to buy FPSC/upgrade it in order to build your game, but you appear to be complaining that you can't change levels after the build is done(or something

). Once you build your game, you can't change your levels
in the compilied game, but you can make changes to your FPM files and then recompile all of the levels with the new changes.
Does that answer your question?
As a believer in Jesus Christ, I am trying to use my passion for game creation for His glory.