I believe there is a Patreon level that gives you access to the nuclear football, which I so dubbed because it has a good chance of nuking your save by setting friendship levels independently, to whatever index you want, with essentially no restriction (AFAIK).
The problem is that the game is complex. Like, MB upon MB of lines of code complex. There are interlocks in the girls' stories that can end up with a situation like the one you had, inconsistent states that make the game unplayable.
The "max-this" cheats are safe, because Runey specifically went to the trouble of making them safe: they cross-check that all the interlocked states are appropriately updated, so that, like in this case, if you are maxed with the twins you are also at the minimum required friendship with ashley. They also set whichever hidden variables need to be set to their appropriate values.
Going backward is a lot more complicated: even something as simple as setting all friendships to 0 isn't guaranteed to work, because there are other variables that have been set and need to be reset. The game does not expect you to see *unique* events *twice*, and so inevitably all those states are not meant to be updated twice, which, again, can leave your save in an inconsistent and unplayable state.
In better news, most events are replayable in the gallery, and you can even make different choices and see how they would have played out. These choices don't affect your save, for better or for worse, so you can go crazy.