Don't remove Glancing Blows from two-handed fighting while moving.
1) Characters are ALWAYS moving, or they are dead. Removing Glancing Blows while moving means no glancing blows, ever. This is a far more significant DPS loss than Devs seem to realize!
2) You have to take 3 feats to get Glancing Blows while moving. Removing Glancing Blows while moving basically means that Greater Two-Handed Fighting does nothing, but still costs a feat.
3) Nobody asked for THF to get nerfed. Also, I doubt that encouraging characters to stand still while swinging a 2-handed weapon will have any effect on DPS lag. (In fact, groups with only THFers tend to have 0 DPS lag.)
Does this change improve gameplay?
No.
Does this change make the game more fun?
No.
Does it improve the performance of the game?
Doubtful.
Please rethink this change before Update 5 goes live.