Well, here's the thing on my two cents on that. Lately from what I've been researching and had to dig stuff deep and far back through the years of the ROM hacking websites, there were talks about people wanting a Castlevania 3 editor (something like reVamp) but with the feature to eliminate and add rooms for a linear type style and since the technology is getting better I was going to ask around on here to see if someone was willing to spend time on seeing how to tie the rooms together properly. On my perspective of messing around with reVamp off and on each room has its own set of rules however leading stairs to them is key and vital to this though it can be other forms of entry as well besides stairs hence why I want to do a rope climbing feature in Legends NES. Now with these set of rules it just has to keep whatever that they have within them because they cannot be changed as these rules are specifically set to these areas though they can be moved around and be something else entirely. The rooms with the doors that represent the checkpoints may have to be looked at though also too those rely on a certain bank address however these rooms cannot be changed so they must remain on having doors for they can't be moved around like everything else. That one room in the Ship of Fools with the ledge things you jump on has to remain in that specific feature to how reVamp has those areas banked for certain other 'traps' or 'hazards' to maintain. I know stuff can be duplicated and even moved around however in order to do this you'll have to rebuild the game from scratch with no other rooms available because everything is somewhat stacked upon each other. I learned this from the first CoA when Optomon and Dr. Mario was trying for their Metroidvania styled game as they should have deleted every other room and should have started from the beginning. I know that this will take tons of time and error but if someone wants to fully make a Metriodvania type game on Castlevania 3 it really can be done.
I may have no programming experience but when I notice shit like that it makes me wonder. Its just up to finding someone out there on this website to see if they are fully willing to literally tear apart and document Castlevania 3. Like I said, the technology for ROM hacking is actually at a really good high point right now for new things to happen. Its just up to the community to see if they want to put in this effort, collaborate, share notes and do this. People say "Oh, this stuff can't be done and all that" though I call bullshit. I've seen certain hacks on this website that have defied these odds. Just takes time, patience and a lot of effort around the frustration to bring this stuff to fruition and hopefully one day reality. Its one of the reasons why I want to find programmers to make Legends NES a thing because I want to have that hack a template for whoever wants to alter that and do their own projects off of it. I know it will take me longer to do than VoH II but I really believe it can be done. Sure I only know simple stuff like finding hex coding for color palettes from an emulator and sprite editing but I notice a lot of stuff ticking around on the game.
I know this stuff can be done. Just need to get a lot of the programmers on here that know on what they are doing together and tear Castlevania 3 apart and document it. Dunno why people are so intimidated by this game besides a lot of sprites and stuff to edit which is nothing different from doing Castlevania and Simon's Quest. Run out of room? Just expand the ROM as it doesn't need to be put on a cartridge as it can be there for freeware for others to play and enjoy. Reason why I got into this stuff in the first place as I don't care about drama this or drama that. I do this shit for fun and to make stuff for others to enjoy.