Should i redo the Seriously glitch?

[i like coupons]

I basically have the normal ones for getting 1 kill, but glitching I cant quit you Dom, THIS! IS! ANNEX! and glitching the acts sometimes does not work sometimes(ex. i beat raam on hardcore without beating the act, got soldier, mercenary, completed act 5 on casual and hardcore but when i beat him on insane, nothing.)

Also, will i get the For the Fallen achievement if i glitched the cog tags? I got 29 right now(when i glitched it i had 21 and it glitched to 27) and im planning to restart the entire campaign to find it so if you know if it will unlock, tell me.