Honestly, I think they need to create new categories for the protocols used for the traditional Internet and divide it into Local Area Protocals (LAPs) and Wide Area Protocols (TCP/IP is the defacto WAP) as well as adding a gateway (like AppleTalk to IP gateways of yore) so that there is more than an airgap (its a different language/protocol as well) separating your network from from the worlds biggest venerable network.

Or, as compute power, storage and hardware get less expensive, running two cryptoledgers for inbound and outbound communications would make it easier to sanitize every bit that enters a network.

I like squid and other products, but I think dropping TCP/IP from the LAN or tranfering all packets in amber (bitledger) would correct a lot of the present shortcomings with security, privacy and unfixable manufacturer defects.