The developer can sign the save files and detect changes like that too.Yes, I definitely could do that, but I avoid such measures as a general rule. I prefer to go the file-editing route. Though it's uncommon, some games actually track whether a player uses the cheat methods a game offers, and it can/will affect various aspects down the line. Side-stepping such functions by directly altering the save data ensures all potential paths remain available, because cheater flags aren't tripped in the process.
If I were solely intent on seeing the lewd content, I could beg for full saves like so many others, but I prefer to go through a game on my own while ensuring that I can fully explore what a game has to offer without spending time grinding away.
I also generally learn various things just by looking at the data. Having some idea of what's in the various game files informs me on what components of the code I might decide to modify, and how to do it without causing errors, in the event I want to change the behavior to some degree.
I do understand, however, that some people don't want to dig through data for any particular purpose, and most likely don't enjoy dinking around with program code. I do enjoy it, however, so I'll keep doing it.
There's not much point in doing it though. While the game does track if you used cheats the only thing it does, is say "You are a filthy cheater" in the achievements screen.