In my opinion it would be handy for the "No Proxy Hosts" setting (under "Tools -> Options -> Manual Proxy Settings -> More...") to have 2 additional checkboxes:
Private network -> for all reserved addresses: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, fc00::/7
Loopback -> for all loopback interfaces: 127/8, ::1, localhost
In our corporate environment, we need a proxy to access anything "on the outside", but need to avoid it for machines on our intranet. So being able to simply enable the "Private network" checkbox would be very handy.