It's quite normal to have that sort of wear after awhile if you want to help prevent it I would recommend a mat to cube on and a case to keep it in when you're not using it, but those small scratches are going to eventually happen.
I've had my Yan 3 for awhile now and I've been wanting to set up again, but I didn't really like how
the lube that used felt. Does anyone recommend any lube for the core/pieces?