These are the currently available codes. They work under latest PCSX2. The only cheat code not included is the one actually opening the level editor; For the E3 demo, you need to open the PCSX2 debugger, navigate to the address 204694ec and set the byte there to 01 to enable it. I wanted to make the code work but sadly didn't have the time. There are also a few other codes included.
the "Level x replace with ..." codes replace the warp room levels with other levels. THere's 24 of them and I have them categorized but I forgot where I put the file. Will upload later.
The "replace cdrom0 with host" is a bit funky: it allows you to use the "Enable host filesystem" option available in PCSX2 to make the game read things not from the loaded ISO but from your actual PC by just running the extracted executable in its root folder. This is a godsend for editing, but it has its quirks. E.g. on my machine (running EndeavourOS/Arch but simpler), the entire file system must be in capitals, except for the root. The root, for whatever reason, is weird. All files and folders in the root directory must have their first three letters lowercase, then the rest will be uppercase. If this isn't upheld, the game will not find the files. In addition, the executable file will not show up in PCSX2's game list by default. You have to manually add the .elf extension to it, since by default it just ends in numbers. You also have to go to the executable's properties and select its root game iso as the iso file you extracted; TWoC does not come on ISO files, it comes on BIN/CUE files. I recommend the linux utilities bchunk for converting to ISO, and bsdtar for extracting the ISO. AFAIK these aren't available for windows by default, but windows does have WSL so I just recommend you use that :^)
Also included is a code by Runpei to disable the timers present that would normally kick you out to the warp room. This means you can take your time with exploring the levels :) Or have the game paused indefinitely, for that matter, since there's one ingame timer and one pause menu timer apparently.
Source code: [WIP; Will be on GitHub]
[Loader]
author=LXShadow, port to early by RatcheT2498
description=no
patch=1,EE,2019e3fc,extended,0803f000
patch=1,EE,200fc000,extended,0c04bc82
patch=1,EE,200fc008,extended,0c064b0b
patch=1,EE,200fc010,extended,3c040044
patch=1,EE,200fc014,extended,348496a8
patch=1,EE,200fc018,extended,af84998c
patch=1,EE,200fc01c,extended,00002025
patch=1,EE,200fc020,extended,0c064ad9
patch=1,EE,200fc024,extended,00002825
patch=1,EE,200fc028,extended,08067901
[Font scale corrector]
author=LXShadow, port to early by RatcheT2498
description=no
patch=1,EE,20130cc0,extended,00000000
patch=1,EE,20130cd0,extended,00000000
patch=1,EE,20468afc,extended,0000001a
patch=1,EE,20468b00,extended,00000018
[Enable all editors]
author=LXShadow, port to early by RatcheT2498
description=no
patch=1,EE,204496a8,extended,003f2028
patch=1,EE,203f2028,extended,00445660
patch=1,EE,20445660,extended,0044b358
patch=1,EE,2044b358,extended,003e1280
patch=1,EE,203e1280,extended,00449630
patch=1,EE,20449630,extended,003de2a0
[Disable visitable loading]
author=RatcheT2498
description=this one's not a port!
patch=1,EE,20469458,word,2e4c4f4c
[Replace e3hub with hub]
author=RatcheT2498
description=Somewhat broken but cool :)
patch=1,EE,20463e3e,extended,00627568
patch=1,EE,00463e42,extended,00
[Replace cdrom0 with host]
author=RatcheT2498
description=All files and folders must be in capitals. Except those in root, those must have their first three letters in lowercase.
patch=1,EE,20100128,extended,00101021
patch=1,EE,201001b4,extended,00000000
patch=1,EE,201001b8,extended,00000000
patch=1,EE,201001bc,extended,00000000
[Level 1 replace with ...]
patch=1,EE,0041b130,extended,07
[Level 2 replace with ...]
patch=1,EE,0041b131,extended,08
[Level 3 replace with ...]
patch=1,EE,0041b132,extended,02
[Level 4 replace with ...]
patch=1,EE,0041b133,extended,03
[Level 5 replace with ...]
patch=1,EE,0041b134,extended,04
[Pause and gameplay timers disable]
author=Runpei
patch=1,EE,20417160,extended,3d000000
patch=1,EE,20425d28,extended,00000000