What happen if I switch faction in different difficulties?

So I reached revered with Outcast and Kymon in elite. Now if in ultimate I decide to kill Anatasia (or whatever her name is) and side with Vigil, can I still access the Outcast and Kymon shops in elite?

No you won’t, changing sides will reset the faction reputation for all difficulties

But you can stockpile augments from Outcast/Kymon’s Chosen before that and have the benefits of all factions at the same time