I understand that stances such as Crouching and Prone were not implemented to save on the animation budget (lol); but with shields taking a more prominent position in the game I feel they should be.
Crouching while wearing (riot armor with) shield should add half the melee damage block to the ranged DT of the player; i.e. crouching with a TiChrome shield should give mechanical, heat and energy DT.
Crouching in general should halve Movement/Evasion/Dodge, but increase ranged accuracy by 25%.
And a new feat: Testudo: prerequisite - Shield Arm
Increase Melee Block to Ranged DT ratio to 2/3rds, add one third of melee damage block to DR.