As far as I've been able to find, pretty much everything has been locked down in windows 8+ regarding network settings (templates) in general which were earlier easily editable by either netsh or going into the registry.. unless you're running a server version, which of course most aren't.
Why was this even done? Not like the normal user will accidently change these settings, for power users, as a gamer myself, I would like to tweak everything possible to get the lowest ping since this is one of the few things you can do on your own side that affects it at least a decent amount, except for having a good router and whatnot. The larger part is up to being lucky with your isp.
So please make it possible to activate and edit the InternetCustom in normal setups.
If it's not possible to do this for whatever reason, please at least make a specific template for low ping desired setups as a gamer, like InternetGaming or similar.