The mobile feat unlocks three passives (as per patch 9): Mobile_PassiveBonuses;Mobile_CounterAttackOfOpportunity;Mobile_DashAcrossDifficultTerrain

new entry "Mobile_PassiveBonuses"
type "PassiveData"
data "DisplayName" "Shared_Passive_Mobile_PassiveBonuses_DisplayName"
data "Description" "Shared_Passive_Mobile_PassiveBonuses_Description"
data "DescriptionParams" "Distance(3)"
data "Boosts" "ActionResource(Movement,3,0)"

new entry "Mobile_CounterAttackOfOpportunity"
type "PassiveData"
data "DisplayName" "Shared_Passive_Mobile_CounterAttackOfOpportunity_DisplayName"
data "Description" "Shared_Passive_Mobile_CounterAttackOfOpportunity_Description"
data "ExtraDescription" "Shared_Passive_Mobile_CounterAttackOfOpportunity_ExtraDescription"
data "Icon" "PassiveFeature_Mobile_CounterAttackOfOpportunity"
data "PriorityOrder" "1"
data "Properties" "Highlighted"
data "StatsFunctorContext" "OnAttack"
data "Conditions" "IsMeleeAttack() and Character()"
data "StatsFunctors" "ApplyStatus(SELF,MOBILE_NO_AOO_SOURCE,100,1);ApplyStatus(MOBILE_NO_AOO,100,1)"

new entry "Mobile_DashAcrossDifficultTerrain"
type "PassiveData"
data "DisplayName" "Shared_Passive_Mobile_DashAcrossDifficultTerrain_DisplayName"
data "Description" "Shared_Passive_Mobile_DashAcrossDifficultTerrain_Description"
data "Icon" "PassiveFeature_Mobile_DashAcrossDifficultTerrain"
data "PriorityOrder" "1"
data "Properties" "Highlighted"

The later is referenced in a few status_boosts such as:

new entry "DASH"
type "StatusData"
data "StatusType" "BOOST"
data "DisplayName" "Shared_Status_BOOST_DASH_DisplayName"
data "Description" "Shared_Status_BOOST_DASH_Description"
data "Icon" "Action_Dash"
data "SoundVocalStart" "NONE"
data "SoundLoop" "Spell_Status_Dash_MO"
data "SoundStop" "Spell_Status_Dash_MO_Stop"
data "StackId" "DASH"
data "TickType" "EndTurn"
data "Boosts" "ActionResourceMultiplier(Movement,200,0);IF(HasPassive('Mobile_DashAcrossDifficultTerrain', context.Source)):StatusImmunity(DIFFICULT_TERRAIN);IF(HasPassive('Mobile_DashAcrossDifficultTerrain', context.Source)):StatusImmunity(DIFFICULT_TERRAIN_MUD);IF(HasPassive('Mobile_DashAcrossDifficultTerrain', context.Source)):StatusImmunity(DIFFICULT_TERRAIN_VINES)"
data "StatusPropertyFlags" "NonExtendable"
data "ApplyEffect" "c8db5bfe-06a2-4847-a496-bac8a11453ef"
data "StatusEffect" "30c73b0a-169a-46f9-9f6f-c3ea19117e38"

So whether the DASH status_boost is applied via a full action or BA it gives the same result.