It's time for me to also contribute something to you guys.
Ifound all the existing exploit loader web pages to be full with (for me personally) unused stuff, which led me to making my own interace for
just loading Loadiine(v2) and WUPinstaller(v1.1).
It's compatbile with WiiU 5.4.0.
Also it's optimized for the WiiU gamepad's screen resolution and uses big buttons (for those of us having bigger fingers
) for navigation.
I thought it could be useful for you, too - feel free to bookmark it on your WiiU.
http://wiiu.suffkoeppe.com
EDIT:
My daughter is 8 years old and she's able to use that site as well - I think it's pretty intuitive