Totally missed that, I just checked a few pages back and couldn't find anything and the front page links to the old save editor so didn't know a new one was out .if you format the text to tree view it will still work when you import the save file in. You can either use json viewer or jstool (both on notepad++). In any case, the save editor that I linked a while back has made some good progress, with only the flags and item adding to inventory being the only things left to do (though you can add items in game anyways so its really only the flags left)
Used to check the forum before and was a patron for about 1-2 years I believe but it got put on hold after I got a new credit card last year and all the games I supported on patron got canceled and kinda put the game to rest after I read about the remake to a new game engine.
Anyhow checked it out and yeah as you mentioned the save editor seems to have pretty much everything except for the inventory edit, which as mentioned you can mostly get in game anyway.