It's spot on. The spending during national emergency alone gives certain options, but caring up the Balanced budget and Emergency deficit control act give him complete control. He talked veto, talked them right into panicking and adding more last ditch efforts to stop him, and he'll use it against them.
But it goes beyond the wall. Yes, this can fund it, but it also funds everything he needs to take them down. Tribunals, OIG, Military and vets. Hell, my disability check might actually see a bump that it hasn't had in 8 years.