It was my plan to try when deplete all the option, and yes, it worked. I've done full wipe of the drive as well. Something terrifying happened and I'm not sure if it was suppose to; on updating firmware when third progress bar was filling up cpu started overheating and fan was working like mad and machine suddenly cut off. I couldn't have turned it on for next 5 minutes, longest 5 minutes ever, as this sp4's warranty is expired (bought it of
ebay). When it finally started back up it finished remaining updates, going hot on the last one again
but this time when it shut down it restarted straight back up. So, so far so good. Just doing normal updates now. Thanks everyone for input. I think I can close this thread as solved.