Possible on standard version?
I've tried enabling the cache function on the standard version 4.0b2, and that seems to work. However, no caching seems to happen. I've read that you need a 2-cpu license to try the cache function. Can I presume this means that it won't work on the standard version, even though you can set it in the admin panel? If this is correct, would it not be better to identify that you can't use it in the panel itself?