If they build from SVN, which seems to be the case, then those commands are probably there.
Get C-Box
Link
Then, extract the xbox iso with it. It will leave you with the default.xbe and other files. Then you can send them via ftp and launch from xbmc. When it loads, press (B).
I do not know if the tool will work with a softmod. I don't see why not. The files loaded off the HDD do not have anything to do with the video mode of the system. I was very busy yesterday, so I did not have time to reply. Hope this helps.