It's simple, load the USB loader GX forwarder and select homebrews and load them from there for now, it will load ALL homebrew apps in 16:9, and so far I cannot load homebrew channel from there. but it's a good workaround for now.
UPDATE: and bump. using the homebrews loader on USB loader GX, select the title loader on the bottom of the screen and load ANY wii channel in 16:9, including the HBC. this includes ALL virtual console games.
Speaking of forwarders, while I really doubt this will work, could someone try using this HBC Forwarder to see if that fixes the aspect ratio problem? HBC Forwarder - GHBC - vWii
I can also confirm that the HBC Forwarder JoostinOnline made/or adapted for vWii works. I ended up dragging HBC to the last page and putting the forwarder channel where HBC was.
The problem is because HBC's current title ID begins with an L I believe, which is the letter of some VC games and Nintendo changed the code to make those VC games display properly. Any channel beginning with a letter that isn't used for VC games should work fine. HBC will get an update to fix it, but there's some other stuff that needs done too.
Now that tueidj has posted his fix, I'm interested in booting certain games with the 4:3 aspect ratio format, as it is the only way I've found for keeping the proper aspect ratio when playing GCN games using Devolution on the Wii U GamePad.
So I've modified JoostinOnline's original forwarder. Channel ID now is LHBC. HBC boots in a 4:3 aspect ratio format. http://uploaded.net/file/lb15fqow
Though I've realized this is not needed until tueidj releases a permanent fix, as the actual fix has to be applied everytime you boot the HBC from the system menu.
I think I'll stick to JoostinOnline's previous forwarder until tueidj releases a proper fix or a new HBC version.