Why are Submersible's save codes unencrypted?
Submersible has a lot of data to save. I use my CSKV format which is designed to be easy to read/write. Development is faster and debugging is easier. Data recovery is also more likely to be successful and I've been able to do this multiple times (usually from users mishandling their save codes when copying/pasting).
Many users express concerns that these save codes make it easy to cheat. Checksums are used for the most important values. This is a sufficient obstacle to make "seeing inside" the project and editing it as being far easier. Seriously, if you want to cheat, enable dev mode and use the cheat commands (or any other dev features implemented). This is not something that can be stopped as Scratch allows editing by design.