I’ve just made a blog that may be really helpful for a lot of people here who make their own Love Live costumes: sifvectorarchive. It contains the graphic elements of the outfits in vector format for anyone to download. People who use heat transfer vinyl for cosplay would be interested. I’d love if you could post this ask and share!

Here is a link to the blog, for anyone interested:
https://sifvectorarchive.tumblr.com/