Not being Renpy based, the savegame unrolling/rerolling system isn't built in. As such I've usually blocked the player from saving / loading in mid conversation. It's been a persistent feedback that people really hate that, so at some point I bit the bullet. It's been 5 hours of pretty intense coding, but iteration #1 is in.
The basic savegame system for dialogs took most of the time; I needed a better way of tracking progression than I'd used up to now. I also had to beat my aging conversation system into supporting arbitrary start points.
Next, there are some places where the state is deeper than just a conversation. For example when you're inside Elsewhere (it needs to track what cards are open, HP, turns left, etc). It also needs to deal with the computer screen, where you could have different menus open.
It's still not truly universal; I didn't add saving in mid-card battle . But hopefully it's one of the features a lot of you have been asking for.