And in another link it says "run this after the first flashing:'echo 0xDEADBEEF > /etc/config/google_fu_mode'.
I have no idea what that command does,I assume it's relative to GFW.Anyway it's up to you.
Keep in mind you're essentially just flashing another black box firmware unless you can read Chinese (and know the forum). Might as well stick to the stock firmware - 'the evil you know', as the saying goes.
I looked in that directory, there's no firmware for R6800.And that post didn't say anything about R6800.Judging by the screenshot, I think he just compiled every device in target Mt7621 from the master branch and add some tweaks.
I understand. I was in a mood to experiment. Will let you all know how it goes, if I get the courage to try it. Currently I am using another Chinese firmware with no issues for over a month.