How to receive the highest defensive bonus?

In XCOM: Enemy Unknown, this post mentions how defensive bonuses are calculated with regard to the amount of cover, perks and additional buffs.

For XCOM 2, I currently have this defensive bonus list:

 - Half Cover:                          +20
 - Smoke:                               +20
 - Hunker Down:                         +30  
 - Half Cover w/ Smoke:                 +40
 - Half Cover w/ Hunker Down:           +50
 - Half Cover w/ Smoke and Hunker Down: +70
 - Full Cover w/ Smoke:                 +60
 - Full Cover w/ Hunker Down:           +70
 - Full Cover w/ Smoke and Hunker Down: +90

What perks or armors are available to further add to these bonuses? For example, in XCOM: Enemy Unknown, the 'Dense Smoke' perk allowed smoke grenades to give an additional +20 defense.