The 5th Circuit court of appeals has already ruled similarly that the SEC's in house courts are unconstitutional, and that Congress can't delegate its legislative/judicial powers to the executive branch in that case under the separation of powers [1], a case that will likely be heard by the SCOTUS. By extension, if that is upheld, the idea is that this same principle could be applied to other executive branch administrative courts like in use at the NLRB.
Congress can Overrule the SCOTUS and the Voters can Change Congress and if things get too Conservative Activist in the SCOTUS and the 1%-5% of the wealthy in the US get too much sway then that's only one Depression Away there from moving back the other direction, A La FDR and another New Deal! And just because any Administrative Law Court and agency is set up under the executive branch does not mean that it was not set up by Congress and is not under Congressional Review where the Executive Branch head of any agency gets reviewed by a Congressional Committee on a regular basis. Congress sets up administrative Courts and any Administrative Law Court NLRB/Other Administrative Law Court can have its decisions appealed to a Federal District Court or a DC Circuit panel of Judges and on up to the SCOTUS.
[1] https://www.winston.com/en/blogs-and-podcasts/government-pro... "Fifth Circuit Holds That SEC’s Use of In-House Courts to Adjudicate Enforcement Actions Is Unconstitutional"