I've been looking for a proper way to make the creased vertices stay in line with the subdivided geometry but it ends up creating an unwanted corner stretching.
I'm trying to get something like this, in this case I'm using a shrinkwrap modifier to get rid of the stretching but it's not a very reliable or practical solution:
So, if anyone know of a proper way to do this I would really appreciate if you could share it, this has been giving me trouble for a long time.