Found one other topic about this, but they only mentioned it happening with grenade-launcher-type ARs. So this may already be known but bear with me.
I noticed the Landscaper shotgun, with its grenade-type explosions aimed at my feet, potentially made my absorb shield add rockets.
After some testing, I believe the rocket absorption works with any type of splash damage from a weapon that harms the user. I say weapon-based because I couldn't get it to work off a mirv grenade, but it did off a rocket launcher explosion, Tiny Tina's Boom Puppy, and off the small blasts of a corrosive Spiker. The Spiker was really surprising, so in a pinch if you're out there, low on launcher ammo and unable to get to a vending machine, you can simply turn pistol ammo into rockets.
Anyone here done more testing with this? I'd be interested to know if it can happen in co-op, or with any elemental rocket launcher (I was using an explosive RL).
It's raining luggage and babies and limbs and Daddy doesn't come home.