Late game help/hints (SPOILERS POST ROOM 46)

I’ve hit a point in Blue Prince where I am starting to wonder what is even next for me, I have obtained Sanctum keys from the safehouse, reservoir, vault, clock tower, and room 46. My only other leads atm are the 9th classroom and that 4 letter padlock above the inner sanctum using the red boiler door. My main issue is that I have a ton of information but seemingly nothing to apply it to, unless it ends up being some konami code type answer. I’m aware of the paintings spelling out something across the blueprint, found the “Castle” text inside the chess piece upgrade room, i’ve read the “A New Clue” book(so many things that could be to anything lol), and I am still suspicious of the Music Room(maybe draft late for sanctum key but still what ab the sheets?). I have only opened two safes, being the shelter and Boudouir. Should I have opened the other ones by now? Is there a point where I should realize? It feels like they all require some random date but that can be so many different numbers it is hard to grasp what point in the game the safes are for. I love this game so much but I am at the point where I wonder if my next steps will continue to snowball or leave me wondering where to go, the painting puzzle seems like my best bet because “Room 8” could be anything. Especially since I had to look up the ladyship’s chamber because I have drafted it twice total including the time I went there with the key because my drafting strategy would have never let me see that room for ages, so it’s a frustrating confliction whether or not to know when I should have access to something or not. ALSO, what line on the room 46 sanctum key note is referring to the safe house? A key held by a king on his throne or in a station left by one of your own?