Precise Interception: Not Bug, explained after discussion

Something being weak doesn’t make it a bug. Give me actual numbers and we can prove to you the math works. Unhide your characters. If you have 140% increased armour, each piece of armour will gain 140% increased armour. If you take the node, your shield would then give 200% increased armour instead of 140%. Add the contribution from each piece to get your total.

All passives are global.

I agree. Gained couldn't be used because it means multiplication after global increasing multiplier. As You mention this mod increases global, partial but only shield.