I think I have somewhat narrowed the issue - sometimes, on world generation, if I try to use dfhack's "exportlegends info" command, it will crash upon generating the legends_plus file. The file works as usual but stops halfway through an artifact entry (usually a book, but not always) and crashes DF. So I tried to look through the artifacts section in DF legends itself, which also led to a crash. I guess this only affected larger worlds because what ever material/item is causing the corrupt artifacts is given more chance to be used. Is there any way to find out which artifacts are causing this issue? If it's a specific creature's leather or something, I could always try deleting that creature from the raws.