In order to use to use rocksdb-blob-store the user need to create path for each Space partition's blobstore. e.g: paths="/mnt/db1,/mnt/db2, ..."
Can you please save this hard work from the user, so he will need to specify only the root dir and all other will be done by code. something like what we did in pmem. See - changed mx-pmem file-name parameter with pmem-path