Hi Jordi,
“Providing another entity with separate addresses (up to /64) from a subnet used on a link operated by the assignment holder is not considered a sub-assignment. This includes for example, letting visitors and/or employees (BYOD) connect to the assignment holder's network, connecting a server or appliance to an assignment holder's network and setting up point-to-point links with 3rd parties.”
An explicit choice was made in this version that specifying fixed boundaries (like a /64) should be avoided to avoid dependencies on specific technology. Please compare version 1 and version 2 of this proposal. Your suggested change would therefore be a partial reversion to a version that didn't have consensus, which would not be appropriate at this point in the process. Cheers, Sander