In our guild, we use the lifetime counter. No need to use fancy spreadsheets - 2.5 hrs before guild refresh, check the lifetime counter for 600 compliance. 1.5 hrs before refresh if short, penalize by mandating zero dmg Rancor x2 and Tank x 1. If short 30 minutes prior, remove them, and put in an alt to do 600. After refresh let them back in. If that locks them for raid rewards, too bad, do your 600.
Have everyone leave the guild and rejoin when no raids are open, to reset their lifetime counter. This way, you're looking for a lifetime counter ending in 000, 200, 400, 600, 800.
When they're short, bump them to reset the counter. No need for screenshots or spreadsheets. I'm the main counter police in my guild, it's really easy to manage this way.
http://www.swgoh.gg/u/diezel
