Take, for instance, Preston Garvey. Without anything he can get 904 of steel (1 steel=0.2 weight) = 180.8. Now give him a peace of armor with "deep pockets", but don't wear it. Armor weight = 2.7. Now it can get 890 steel=178. Fine. Now wear this peace of armor. Still can get 890=178. Deep pocket don't work? But now unwear this armor but keep in inventory. It can get 940 steel=188. So if more switch on/off wear armor resault the same. "Deep pockets" on companion works only if it is unweared.