Mikiraus There's a few issues I've seen that are still in the current version after starting over.
I think Ash's events still aren't quite triggering things correctly. If on the slave path with 2 at the time of the arm-wrestling, winning gives you +1 love level, and losing gives you +1 slave level (so either 1 and 2 or 0 and 3 for the levels in the phone's progress checker). If you won the arm-wrestling, regardless of whether you kill or just paralyze the sinner with the Needle in her next event, it changes her progress to love 1 and slave 3. It says "If only he had won..." below the levels, even when I did.
The option to visit the sinners in the cages disappears after starting the third act and getting the store/waifu house.
Zero Two's slave level doesn't go up after her slave level 1 event. Her progress stats are 0 and 1 before the event and still 0 and 1 after it. It doesn't keep you from continuing to her next slave event, but it makes it so that the text in her progress tracker doesn't make sense. You are also unable to do her open world slave level events until you've done the event for the level after that (i.e. 2 unlocks after 3, 3 unlocks after 4, and 4 unlocks after 5 when you taken her into her world).
If an event changes things to a different day (ex. Casca's level 6 event starts Saturday and you gain control again on Sunday morning), it doesn't reset your times worked, trained for the day, or if you've done anything with the sinners (both the Waifu House ones and the others). In the Casca example, training beforehand at the dojo on Saturday results in getting the "I already practiced today." message for the rest of that Saturday AND that Sunday. You're also able to work 1 less time than you should be able to at the library on Sunday.
Mai's slave level one event starts Monday morning in class and ends Wednesday afternoon. Tuesday is skipped.