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.
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