okay reading some of this I'm getting a series of impressions;
1: This is basically unsuited for RenPy in the form they currently have it, mostly because it seems to be loading a bunch of high-res png's at once and that consumes a lot of memory when you're talking about a frame-by-frame animation (rogue like by oni gets around this by having simpler animation).
2: Asset pipeline is fucked; to a degree greater than SU ever was even. as SU's bottleneck seemed to be a lot more at the ""Unity"" end (along with the unforgivable sin of a registry-based-save).
2a.: part of the reason the pipeline seems "fucked" is the lack of any placeholder art or a "frontier"-edge.
that Act II chapter I is nearing completion should mean Act II is mostly written, and that Act III (if there is an Act III) has a solid series of arcs already laid out for it, with the layout of key scenes planned/thought out or in the process of rough sketches that the writer and artist can use to get a feel for each other's intentions before serious illustration energy is potentially wasted.
Act II being mostly written means almost every background and new locations for Act II should be at the very least in a state where they are line art awaiting inking and coloring, or even in an "advanced first draft"-state intended to be replaced but "good enough for testing purposes".
I presume, since there's all sorts of hints in the game already, that hogsmeade is in the future. Have the characters for this location been thought out? character art drawn? I assume there's a hotel and possibly a brothel there we're going to be seeing.. has the flow chart of what goes where and how the rooms connect been planned? I mean there seems to be enough hints that there's going to be a potion lab and a library added on, has the librarian been given a sketch?