This is one of the feature from Hoppip Streamlined heisting I suggested to get this mod for full feature unless you have other mods that not compartable with this.
So yeah like it's said it Makes Bulldozer armor scale with difficulty and behaves like Heavy SWAT armor.
here is the armor scale Table for it.
X1 for Normal
X1.5 for Hard
X2 for Very Hard
X3 for Overkill
X4 for Mayhem
X6 for Dead Wish
X8 for Death Sentence
This fully applies to Armor plates and only 50% to visors.