I don't know and it would be interesting to know if it makes any difference.
What I wouldn't do is to point it at a relatively slow shared folder. As it's a cache it should work fine pointing it to (fast) local storage. I suspect that if it's pointing somewhere slow it'll make things worse. There's also (I read) a potential security issue, in that the cache will contain code that is executed. So presents a vector for hacking if it's not locked down enough.
What I wouldn't do is to point it at a relatively slow shared folder. As it's a cache it should work fine pointing it to (fast) local storage. I suspect that if it's pointing somewhere slow it'll make things worse. There's also (I read) a potential security issue, in that the cache will contain code that is executed. So presents a vector for hacking if it's not locked down enough.