Take the entire project away from NASA. Establish a separate independent government funded not-for-profit enterprise with its own management team and allowed to chart it’s own course, including whatever use of private contractors and private produced technology solutions that IT deems worthy and efficient for success of its one singular mission. Fund it with all that had been designated for SLS/Orion and offer private contractors a piece of the action as needed; by that I mean technological inventions, means and productions that may serve the government’s purpose as well as serve a private enterprise purpose; with the government’s purpose being foundational-exploratory and not as competitor to private enterprises.
Why not-for-profit?