I can't speak for this game in particular, but it is VERY rare in general, a full save for any game would be all switches and variables on or off (whatever you even mean with that in regards to variables, as they are usually a number(when speaking RPGM), and you would have no way to know what their max value would be.
To try and cheat out a full save, you really would need to spend some time to learn how the game code actually works, to know what values to set for what variables and switches (And there could also be plugin stuff that might make more actual code variable in some cases you would have to set to certain values too, that wont be accessible via such a cheat plugin)
I am aware that it wouldn't necessarily be all on or all off, but by testing both extremes, I can slowly (probably yknow, turn half off, half on, or bit by bit) guess what each bool (which is what I was referring to as switches, my B on that one I haven't worked on programming in a while) is supposed to mean, IIRC the variables all had names (The bools didn't some were just blank) so I could somewhat guess what they were referring to (like affection data or something, my memory's pretty fuzzy on this stuff, its been a month since I've looked at any of this.) and none of those seemed like they had anything to do with the gallery, though I did try setting those to extremes as well. I also looked at the items and stuff because I know that some more advanced rpgmaker games use those as a way to store data (idk exactly why, but its probably a limitation of rpgmaker that they have to work around using that) so I checked that as well, the software I was using allowed me to "scroll" all the items even if I had none of them, and, there were hundreds of blanks (that usually happens in rpgmaker games in my experience, no idea why, if I had to guess its probably due to how the cheat menu works, so I guessed that those were actually just nothing, might not be tho idk) but none of the items were things that I didn't actually encounter in game (like food and whatever else I remember being in this game) If I had to guess now looking back, the game likely stores the gallery save data somewhere completely different than regular saves, or it stores them in a way that the cheat menu I was using didn't account for at all, and actually looking into the code is a bit more than I care to do for a random goon game ngl.
TLDR: I wasn't expecting full on and full off to actually work, but with my limited knowledge of coding, it should've changed things, like full on makes half gallery visible or something, and it didn't. some of the scenes that were seemingly accessible (as in, you can see them in game but not in gallery) just didn't have any sort of integer, bool or anything associated with them, and I'd probably have to look into the code proper to understand how the gallery works, something I'm not gonna do.