Oke.
After some testing, I found some "things", that can be polished, and are not a big of a deal.
1. There is something like a bug, where the "crusty key"-tree won't change his dialog after you brought him the Lilith. Making impossible reobtain the crusty key.
This might be a "miss progress flag" issue, because only happened to me when doing things a bit too quicker. I still have to find which flag is the "un-blocker".
2. There is a light glitch when you go to basement while on night. Not always trigger, but when leaving the basement, the light setting reset to day time.
This can be corrected with some correction on which value is automatedly assign when leaving the basement, so it shouldn't be much of a problem.
3. Base on the basement, if there is a Deathcandle, close to the door of the cabin, and you move down while on night, you can see it, just like if you were outside.
I know this is a bug product of how is insert the basement on the whole map structure, so maybe, making the stairs set the value of daytime to just day, when moving down, while storing the value of the current setting might work.
Still this depend on how you build the whole system, I'm just assuming you used a world-type variable for daytime.
4. When walking around the Research Outpost, the upper walls of the "contained-red-black-hole-thing" seems to not have been coded right, for when someone walk behind.
It's a minor issue, and I know you know how to do it right, since the rest of the walls work just fine.
Now random stuff, that isn't necessarily and issue
[Number 5 might be an easter egg or an error. Not sure]
6. For more that I try to get it right, I can't manage to get the right chest size for the ritual.
Don't know if it's a fault from my part, but when trying to get it carefully. 1. get the message of too small, 2. get the message of too big. I don't know if there is a middle size I am just missing, or if this tree is just mocking on me...
7. I'm not sure if it was your case, but when saying that sometimes the true Harpy seems to doesn't spawn, it might be in reality, just under a tree... No, really. Right in the base of the three texture.
It's so similar in colour, that just for a few pixels, it can't be noticed, even while the tree is translucent
[Notice: This just happened to me with a few mushroom, I haven't tested it with every kind]
Anyway. I will keep trying to find every detail, and find a way to replicate it, so you can have it easier to solve.
For what I have at the moment. It's a good section, more intuitive (or guided) than others, pretty fun after all.
That's all I have for now. Have a nice evening