Agreed, he’s exploited a process to the point of circumventing the separation of powers.
And guess who isn't going to like that one bit? Yep .. Congress. Congress, whether Dem or Pub or Lib or Conserv or whatever isn't going to like having *their* authority stepped on by some mere extra-constitutional orders from the executive branch.
After the Dem Love Fest of retaking two out of three branches of government wears off, it'll be the Dem Congress who turns on their Dem Executive leader first, for cutting them out of the equation with these 'Czars' ... you heard it here first :)