I depends on what system you have and the original firmware was.
IIRC, if it came with 3.55 or lower, you may be able to downgrade it.
At the moment, it is no for the faint of heart though.
When the E3 flash hits the market you might be able to use that (if you are on a NOR console (doesn't work yet with the NAND flash consoles)).
I don't know what you found as an answer, but this may be some more helpful info to you.
Enjoy your stay here.
I would much rather go to my grave not needing my gun, than go there wishing I had it.