I hate UUIDv4, don't care about the rest. UUIDv4 is just random bytes with hyphens inserted in random places and some bytes reserved to indicate that this is in fact a UUID. This is wasteful and stupid
You aren't supposed to store the hyphens, and that's the same for all versions.
Is reserving 6 bits really that bad?
You can use different encodings based on context, just like with a random blob of bytes.