"brings in lots of money for the Treasury, available for any spending an Administration wants to hide with a cover"
While I agree that is what happened starting in 2012 with the NWS, likely for Obamacare, I don't see this as tenable in the long term. It's unconstitutional per Article I, Section 9, Clause 7. "No Money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law." Taking the private shareholder profits for Congress to spend for public use doesn't make sense. They would need to complete the Nationalization so they are not publicly held. Otherwise, it's a taking and will be more difficult to argue otherwise the longer it goes.
The only reason it's not now is because the shareholders still exist, so they haven't technically "taken" the company< with the notion that the Conservatorship is temporary and the property will be returned.