the post( lifehacker, not mine) was made on august 28... when did 4.0 come out...I accidentally updated after installing and all is good. I did the hack about a week ago and updated firmware 20 mins later 29/8 I make no promises but the crew that put out this method seem vaguely/fairly confident that it is safe-ish (hows that for a definitive answer)
think it's pretty safe because it's all loaded of the sd card...I imagine you could un-install-remove sd and update when the next patch comes out
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